Communicable Disease Epidemiological Profile

COMMUNICABLE DISEASE EPIDEMIOLOGICAL PROFILE

Central African Republic and Chad

Disease Control in Humanitarian Emergencies (DCE) Global Alert and Response Department (GAR) The Communicable Disease Epidemiological Country Pro- file series was conceived and developed by the WHO team for Disease Control in Humanitarian Emergencies (DCE), to provide up-to-date information on the major communicable disease threats faced by the resident and displaced populations in emergency affected countries.

The information provided aims to assist with the public health strategy, prioritization and coordination of communicable disease control activities between all agencies working in such countries.

Diseases have been included if they fulfil one or more of the following criteria: have a high burden or epidemic potential, are (re) emerging diseases, important but neglected tropical diseases, or diseases subject to global elimination or eradication programmes.

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COMMUNICABLE DISEASE EPIDEMIOLOGICAL PROFILE

Central African Republic and Chad ii

CENTRAL AFRICAN REPUBLIC AND CHAD © World Health Organization 2009

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Communicable disease epidemiological profile Introduction Part Acknowledgements Contents diseases communicable high-burden for guidance and technical information disease Country-specific Part Chad and Republic African Central outbreaks, disease communicable of recent Summary Part (sleepingsickness) trypanosomiasis African Influenza (human A(H5N1) infection) (human Influenza Bacillary dysentery (shigellosis) dysentery Bacillary Diphtheria rationale Document HIV/AIDS Cholera crisis humanitarian the to Background HepatitisE Diarrhoeal diseases (others) diseases Diarrhoeal (ALRI) infections lower Acute respiratory Target audience Purpose Chad and CAR in diseases communicable high-burden Priority Influenza (seasonal) Influenza Influenza (avian) Influenza I I I II I

......

...... Communicable disease epidemiological profile epidemiological disease Communicable ......

77 45 24 49 29 1 79 69 39 35 13 17

1 7 1 6 3 3 3 3 v iii CONTENTS iv

Leishmaniasis (cutaneous and mucosal) ...... 90

Leishmaniasis (visceral) ...... 94

Leprosy ...... 98

Lymphatic filariasis ...... 103

Malaria ...... 109

Measles ...... 117 Meningococcal disease (meningitis and meningococcal septicaemia) ...... 127

Onchocerciasis (river blindness) ...... 134

Pertussis (whooping cough) ...... 139

Poliomyelitis ...... 145

Rabies ...... 153

Rift Valley fever (RVF) ...... 158

Schistosomiasis (bilharziasis) ...... 168 Soil-transmitted helminthiases (ascariasis,

...... CENTRAL AFRICAN REPUBLIC AND CHAD hookworm infection, trichuriasis) 174

Tetanus ...... 179

Tuberculosis ...... 182

Yellow fever ...... 196

Part IV Annexes ...... 203

Annex 1 ...... 205

Annex 2 ...... 218

Annex 3 ...... 219

Annex 4 ...... 229

Annex 5 ...... 231

Communicable disease epidemiological profile Walter Kazadi, Mona Lacoul, Christine Lamoureux, Casimir Manengu, David David Manengu, Casimir Lamoureux, Christine Mona Lacoul, Walter Kazadi, Gabrielli, Albis Diouf, Renu Ousmane Dayal-Drager, Chitsulo, Lester Cherian, Meena Chauvin, Brouwer, Jan Claire Yves Biswas, Chartier, Gautam Bertherat, Eric Bartram, James Bal, Harveen Annunziata, Abela-Ridder, Giuseppe Bernadette acknowledged: gratefully is contribution their and document this of thedevelopmentand review in involved were The following (POL). Initiative Polio Eradication (HAC) the and Crises in Action of Health (GMG) cluster Management the and General cluster; the in (SES) Services Staff and Security (HSS) cluster; Services and Systems Health the in Technologies (EHT) Health of Essential department the cluster; (NMH) Health Mental and Diseases Noncommunicable Development the and in (NHD) Health for Nutrition Violence and (VIP) Prevention and Injuries (FCH) cluster; Health Community and Family the in (IVB) Biologicals Vaccines and Immunizations, Development and (CAH), Adolescent Health and of Child departments the cluster; Stop TB (STB), HIV/AIDS and Control of Neglected Tropical Diseases in the HTM (GMP), Programme Malaria Global the (HSE) cluster; Environment and Security Health (PHE) the in Environment and (FOS), Health Public Diseases Foodborne and Zoonoses (TDR), Safety, Food Tropical Diseases in Training and Research for Programme (EPR), Special Response the and Alert Pandemic and Epidemic of thedepartments includes The Group Working organizations. international and and nongovernmental agencies otherUnited Nations health, of ministries offices, country and regional to WHO issues disease on communicable support tional and opera CD-WGE The Chad. technical and Republic provides African Central the for WHO ofrepresentative the office (AFRO), Africa the country for Office Regional (DCD) WHO Control and at the Prevention Disease of Communicable Working Group (CD-WGE) Division on Emergencies the headquarters, at WHO Diseases Communicable the was by produced profile disease communicable This (WHO). Organization (HSE) World Cluster of the Environment Health and Security Health the in (GAR) Department Response and Alert Global of the (DCE),Emergencies part Humanitarian in Control Disease on unit the by edited was document This Acknowledgements Communicable disease epidemiological profile epidemiological disease Communicable

ACKNOWLEDGEMENTS v vi

Meddings, Elizabeth Mumford, Zinga Jose Nkuni, Salah Ottmani, Shamim Ahmad Qazi, Xavier de Radiques, Aafje Rietveld, Nikki Shindo, Peter Strebel, Jos Vandelaer, Kaat Vandemaele, Zita Weise-Prinzo, Sergio Yactayo, Ahmed Zouiten. Editorial support was provided by Mary Roll-Vallanjon. Maps were provided by Mona Lacoul. Contributions to previous risk assessments from the following focal points have also been incorporated: Jorge Alvar, Andrea Bosman , Claire-Lise Chaignat, Alice Croisier, Alya Dabbagh, Katya Fernandez-Vegas, Olivier Fontaine, Pierre Formenty, Antonio Gerbase, Pascale Gilbert-Miguet, Alexandra Hill, Angela Merianos, François-Xavier Meslin, Michael Nathan, Benjamin Nkowane, Asiya Odugleh-Kolev, William Perea, Cathy Roth, Johannes Schnitzler, Pere-P. Simarro. We would like to thank the Office of Foreign Disaster Assistance (OFDA) of the United States Agency for International Development for their support in develop ment of this document. CENTRAL AFRICAN REPUBLIC AND CHAD

Communicable disease epidemiological profile PART I

Introduction

3 Purpose The purpose of this communicable disease profile for the Central African Republic (CAR) and Chad is to provide up-to-date information on the major communicable disease threats faced by the resident and displaced populations in these two countries. The purpose of the information given herein is to assist with the strategy for, and the prioritization and coordination of, communicable disease control activities between all agencies working in these countries.

Target audience The information in this document is essentially addressed to public health professionals working for the population in the Central African Republic and Chad.

Document rationale The epidemic-prone and endemic infectious diseases have been selected in order to outline the burden of priority communicable diseases. Where available, data and disease-specific guidelines for their prevention and control are given. Information is also included on recent outbreaks. The quantity and quality of data are com- INTRODUCTION promised by the duration, nature and severity of the humanitarian crisis in these countries that has severely affected health systems and programmes. I Background to the humanitarian crisis The humanitarian crisis affecting CAR and Chad is multifactorial (see Annex 1 for a chronology of events). II Since becoming independent, both countries have been afflicted by political instability and violence that has been exacerbated by their proximity to Sudan.1 The humanitarian crises in CAR and western Chad should be seen, therefore, in the context of a subregional situation that involves the southern part of Sudan. III Cross-border hostilities have resulted in the displacement of populations, either as internally displaced persons (IDP) or refugees. The political boundaries of the Central African Republic, Chad and Sudan are shown in the map below. IV 1 Please refer to the Sudan communicable disease epidemiological profile in this series at http://www.who.int/ diseasecontrol_emergencies/toolkits/en/.

Communicable disease epidemiological profile CENTRAL AFRICAN REPUBLIC AND CHAD 4

Communicable disease epidemiological profile epidemiological disease Communicable Political boundaries of the Central African Republic, Chad and Sudan 5

There are internally displaced persons (IDPs) and refugees in camp settings both in CAR and Chad. These populations live in emergency settings, and the epidemiological problems connected with their presence are specific. Current estimates indicate that around 100 000 refugees and 200 000 IDPs are in CAR, and 300 000 refugees and 180 000 IDPs in Chad (further information may be found in the resource documents listed in Annex 2). The effects also have repercussions on otherwise unaffected bordering states such as Cameroon and Nigeria. The political instability amplifies background problems related to climate and development that have traditionally caused a high burden of morbidity and mortality, e.g. recurrent natural disasters (floods and drought), infectious diseases (malaria, meningitis, HIV/AIDS), and malnutrition. CAR and Chad have suffered decades of political instability and armed conflict, the consequences of which are reflected in their deteriorating ranking in the UNDP Human Poverty Index (HPI) and Human Development Index (HDI): CAR – HPI = 98/108, HDI = 171/177; Chad – HPI = 108/108, HDI = 170/177. The HPI particularly reflects hardship in the health area as it measures the proportion of the population not expected to survive beyond the age of 40.

At a systemic level, the chronic nature of the crisis has resulted in the destruction INTRODUCTION of much of the basic infrastructure (e.g. drinking-water and sanitation) and over- loaded the few remaining services. Health systems and programmes are mostly suboptimal, damaged, looted or destroyed and have not received any investment for several years. The cumulative effects on the population are evident in the key I national health indicators and other statistics (Annex 1). In the case of < 5 mortality per 1000 live births, figures have increased since 1990: for CAR, from 173 to 175; for Chad, from 201 to 209. The crisis is compounded by attacks that increasingly target humanitarian workers. II Given the continued political instability and hostile cross-border activity, further influxes of refugees and IDPs may be anticipated. On the other hand, the repatriation of currently displaced populations remains unlikely. III The precarious state of the health infrastructure means that the threat and potential impact of an infectious disease event (export, reintroduction, amplification) or natural disaster (floods, drought) are genuine. Disease surveillance and notification at national and international levels are severely IV

Communicable disease epidemiological profile CENTRAL AFRICAN REPUBLIC AND CHAD 6 9. 8. 7. 6. municable diseases with potential for amplification. potential with diseases municable com endemic the and potential outbreak with diseases communicable priority the for control both and response prevention, detection, disease and measures health approach to public or IDPs) on acoordinated focus of refugees should concentrations or population the general (for strategy The health mortality. and ity morbid to reduce interventions similar requiring and characteristics similar with comparable, are issues the varies, country each in context specific the Although recommendations. WHO with accordance implemented in and planned be should Vaccination campaigns disruption. by vaccine-supply compromised further is it place, take does whenand it to prevent outbreaks insufficient is zation immuni routine diseases, communicable high-burden vaccine-preventable, For the 2. 1. Chad and CAR in diseases communicable high-burden Priority bulletin. cal epidemiologi to produce aweekly is that Chad eastern up in set been has system However, surveillance emergency document. an this covered in diseases of the somefor information of epidemiological lack asa is reflected This compromised. Communicable disease epidemiological profile epidemiological disease Communicable 2 5. 4. 3.

HIV/AIDS Poliomyelitis Malaria Meningitis Tuberculosis. http://www.who.int/hac/crises/tcd/en/. Diarrhoeal diseases (cholera, bacillary dysentery ( dysentery (cholera, bacillary diseases Diarrhoeal infections tract lowerAcute respiratory Measles Hepatitis E Hepatitis 2

Salmonella Shigella, ))

- - - - PART II

Summary of recent communicable disease outbreaks, Central African Republic and Chad

to WHO from January 2000 to August 2008 August to 2000 January from WHO to reported as outbreaks, disease communicable Republic: African Central a http://www.who.int/csr/don/archive/country/en/index.html. Source: Month/year April 2008 April February 2000 February February–June 2001 February–June 2004 May 2003– December 2005 January–June 2006 November 2008 February 2007– November 2008 January 2007– December 2008 April January–June 2002 January–June 2002 January–April 2002 2003 January–May 2003 June–October 2004 January–June 2004 March–April disease burden. disease Country-specific under disease specific each for III Part in given is location outbreak possible, Where Disease Yellow fever Yellow Meningococcal disease Meningococcal (NmA +W135)(NmA disease Meningococcal Measles Measles fever Yellow (NmA) disease Meningococcal Measles WPV1) (imported Polio Measles Measles fever Yellow Measles Shigellosis Measles (NmA) disease Meningococcal a Cases Communicable disease epidemiological profile epidemiological disease Communicable 1040 1816 443 225 287 495 379 195 116 86 45 43 2 1 1 1 Deaths 343 86 80 23 36 14 18 19 11 1 1 0 5 0 0 7 Case-fatality ratio (%) ratio Case-fatality 16.2 16.2 18.8 16.0 13.0 19.4 11.1 2.2 6.6 0.9 9.2 50 6.1 0 0 0 IV III II 9 I SUMMARY OF RECENT COMMUNICABLE DISEASE OUTBREAKS 10 CENTRAL AFRICAN REPUBLIC AND CHAD a http://www.who.int/csr/don/archive/country/en/index.html. Source: December 2000 to August 2008 August to 2000 December from WHO to reported as outbreaks, disease communicable Chad: Communicable disease epidemiological profile epidemiological disease Communicable April 2004 April 2004 June–September camps Refugee 2004 September 2005 January–May 2007 March–April Refugee camps Refugee 2005 January February 2001 February 2000– December 2001 July–August 2003–present 2007 March–May Month/year January–March 2005 January–March 2006 March–April 2006 June–December 2007 February–June disease burden. disease Country-specific under disease specific each for III Part in given is location outbreak possible, Where (NmA) disease Meningococcal Cholera E Hepatitis Measles W135) some predominant, (NmA disease Meningococcal (Nm W135)(Nm disease Meningococcal (NmA) disease Menigococcal Cholera WPV3) and (WPV1 Poliomyelitis (NmA) disease Meningococcal Disease (NmA) disease Menigococcal (NmA) disease Meningococcal Cholera Measles a Cases 20278 1442 3579 3557 3910 1633 200 387 350 147 86 31 19 8 Deaths 401 164 516 113 46 68 53 16 17 4 0 3 0 1 Case-fatality ratio (%) ratio Case-fatality 13.7 11.2 4.2 2.5 3.2 3.2 0.7 9.7 4.1 5.1 21 0 0 8 PART III

Country-specific disease information and technical guidance for high-burden communicable diseases

13 ACUTE LOWER RESPIRATORY INFECTIONS (ALRI)

Country-specific disease burden Central African Republic The under-five mortality rate is 175 per 1000 live births.3 Approximately 19% of these deaths are attributed to pneumonia.4

Chad The under-five mortality rate is 209 per 1000 live births.3 Approximately 23% of these deaths are attributed to pneumonia.4

Description Infectious agent Bacteria: the most common are likely to be Streptococcus pneumoniae and Haemophilus influenzae type b (and Staphylococcus aureus to a lesser extent).

Several respiratory viruses, notably respiratory syncitial virus (RSV). ACUTE LOWER RESPIRATORY INFECTIONS (ALRI)

Case definition Clinical description I ALRI include bronchitis, bronchiolitis and pneumonia (bronchopneumonia and lobar pneumonia). Pneumonia is the most severe and is fatal in 10–20% of cases if inappropriately treated. Pneumonia. Cough or difficult breathing and breathing 50 times or more per minute II for infants aged 2–11months; breathing 40 times or more per minute for children aged 12–59 months and no chest indrawing, no stridor nor general danger signs.* Severe pneumonia. Cough or difficult breathing and any general danger sign* or chest indrawing or stridor in a calm child. III In infants aged less than 2 months, the presence of any of the following indicates severe pneumonia: cough or difficult breathing and breathing 60 times or more

3 UNICEF/WHO, 2006. See: State of the world’s children. New York, UNICEF, 2008 (www.unicef.org/sowc08/ IV statistics/tables.php). 4 UNICEF/WHO, 2004.

Communicable disease epidemiological profile 14 CENTRAL AFRICAN REPUBLIC AND CHAD Depends on the infective agent. Usually 2–5 days. Usually agent. infective on the Depends Incubation period droplets. through Airborne, Mode of transmission * or minute per Communicable disease epidemiological profile epidemiological disease Communicable area. adefined in year the of time for that number expected above the of cases number the in increase An thresholdAlert 5 years). under aged (and children among season rainy the in highest is incidence settings, tropical In Seasonality Worldwide. distribution Geographical pneumonia. acquiring of children risk relative the may increase low temperatures and pollution development. air Indoor and transmission for ALRI factors of major presence risk the given of age years five under children in death and of disease amajor to be cause likely are ALRI of(e/cy) 5. age the until year episodes/child 0.29 estimated an represents This admission. hospital require 11–20 year, per of episodes which of pneumonia episodes new 151 million is million In developing countries, for the under-fiveage group, the estimated disease burden General Epidemiology phase. symptomatic the during Usually agent. infective on the Depends period Communicability any general danger sign.* danger general any vomiting; convulsions; lethargy or unconsciousness. or lethargy convulsions; vomiting; persistent breastfeed; or drink to inability 5years: to 2months aged children for signs: danger General grunting, or grunting, nasal flaring, or flaring, nasal fever, or or or lowtemperature, body 15 Risk factors for increased burden Population movement allows contact between non-immune and infected individuals and increases transmission of the pathogen. Overcrowding increases the risk of transmission which is spread by droplets and compounded by poor ventilation. Poor access to health services. Prompt identification and treatment of cases are the most important control measures. Poor access to health services may delay or prevent adequate treatment, without which the case-fatality ratio can be very high (20% or more in emergency situations). Food shortages. Malnutrition, vitamin A deficiency, low birth weight and poor breastfeeding practices are important risk factors for development of the disease and increase its severity. Lack of safe water and poor sanitation. Unsafe water, poor personal hygiene, insufficient hand-washing and inadequate ventilation increase the risk of spread of respiratory infections.

Prevention and control measures ACUTE LOWER RESPIRATORY INFECTIONS (ALRI) Case management The priority is the early recognition of symptoms in the community diagnosis by health-care workers and initiation of appropriate treatment of cases. Integrated man- I agement of illness should be practised for any sick child seen by a provider trained in the WHO and UNICEF Integrated Management of Childhood Illnesses (IMCI).

Non-severe pneumonia II In countries with low HIV prevalence, 3 days of antibiotic therapy (oral amoxicillin and co-trimoxazole) should be used in children aged from 2 months to 5 years. Where antimicrobial resistance to co-trimoxazole is high, oral amoxicillin is III the best choice. Oral amoxicillin should be used twice daily at a dose of 25 mg/kg per dose.

Severe pneumonia IV For management of HIV-infected children, newly developed WHO treatment guidelines should be used.

Communicable disease epidemiological profile 16 CENTRAL AFRICAN REPUBLIC AND CHAD Annex 3 Annex in emergencies in health Child See with X-rays. difficult may be malnutrition severe with for children of pneumonia diagnosis the to note that It< 11 important is to hospital. cm) referred be should or MUAC oedema pitting (mid-upper-arm circumference) or bilateral Score, (weight-for-height children < 3Z index malnourished Severely to pneumonia. due of death risk the increases this as assessed, be should of malnutrition Signs instructions. treatment antibiotic with compliance including care, on home-based of non-severe cases to carers given be should advice Proper for cases. severe necessary is of low glucose blood management.of Prevention case integrated warm) are part keeping young infants cold (especially from fever, protection high to reduce and antipyretics indicated, if A vitamin to avoid malnutrition, feeding continued as such measures Supportive Very pneumonia severe Communicable disease epidemiological profile epidemiological disease Communicable suboptimal. generally is coverage Immunization of ALRI. impact the reducing in effective are conjugate immunization pneumococcal and pertussis measles, Hib, Immunization Prevention

mentary feeding, should be ensured to avoid malnutrition. ensured be should feeding, mentary comple appropriate and breastfeeding exclusive including nutrition, Adequate improved. be should coverage Immunization seeking. for prompt signs care- danger out on early carried be should education Health of disease. severity and impact the reduces measles and pertussis theria, diph against Immunization workers. health-care training and clinics mobile developing awareness, community raising through particularly antibiotics, effective with treatment and diagnosis improve to early made be should Efforts 2–59 months. aged children in pneumonia severe for very chloramphenicol injectable choice than abetter is gentamicin plus injection ampicillin Injectable pneumonia. severe with to children given be may amoxicillin oral is available, not injection and difficult is referral Where antibiotics. and prescribed pneumonia having as fied classi are before they bronchodilator inhaled of rapid-acting atrial given be should and/or lower indrawing chest breathing fast and wheeze with Children . - - - 17 African trypanosomiasis (sleeping sickness)

Country-specific disease burden Central African Republic CAR has four foci of transmission: Ouham (Ouham prefecture), a continuation of the Mandul focus in Chad; Haut Mbomou (Haut-Mbomou prefecture), continuing the Tambura focus in southern Sudan; Nola-Bilolo (Sanga-Mbaéré prefecture), continuing the Yokadouma focus in Cameroon and Lobaye (Lobaye Prefecture) continuing the northern Equateur focus in the Democratic Republic of the Congo (see map of CAR prefectures in Annex 1). African trypanosomiasis is a rural and chronic disease, and hence mobile teams are the most effective response. However in the Ouham focus, this is not possible as a result of the current situation, and the vast majority of cases are detected passively, in health facilities, during the late stages of disease. As a consequence, those infected act as a reservoir in the villages for the vectors and this in turn creates the potential for further human transmission. During 2002, the number of new cases reported in the Ouham focus was 137; however in 2007 it was 610, 70% of which were detected by passive screening. SICKNESS) (SLEEPING TRYPANOSOMIASIS AFRICAN As indicated above, there are many disease foci in countries bordering on CAR. The disease evolution in CAR depends in many ways on the epidemiological development of these bordering foci. Such epidemiological interdependence I occurred during the Sudanese and Congolese crises in the case of the border regions of Haut Mbomou and Lobaye.

Chad II Areas of transmission are specifically in the southern border areas as indicated above, which are continuations of the northern focus of Ouham in CAR. As a result of insecurity, refugee populations originating from rural areas of CAR have settled in southern Chad. III

Description Infectious agent IV Protozoan: Trypanosoma brucei gambiense (chronic disease) and T. b. rhodesiense (acute disease). In both cases, the outcome is death if the disease is undiagnosed

Communicable disease epidemiological profile 18 CENTRAL AFRICAN REPUBLIC AND CHAD Case classification Case fluid (CSF). or cerebrospinal aspirates node lymph blood, in of microscopy) trypanosomes (by Visualization diagnosis). (for Parasitological for T. possibly and b. gambiense mainly T. b. rhodesiense for assay: microscopy. Immunofluorescent by confirmed be must result positive a no disease; is there that T.b. indicates only). CATT result Anegative gambiense (CATT) test (for trypanosomiasis agglutination Card screening). (for Serological tests Laboratory The disease is always fatal without treatment. treatment. without fatal always is disease The death. and coma somnolence, wasting, (when to body leads not treated) disease the of progression The natural even years. or months several for maylast disease The apparent. involvement are system nervous of central signs and somnolence Cachexia, system. nervous central the attack and barrier blood–brain the cross involvement). (neurological stage Parasites Second rash. and oedema local anaemia, lymphadenopathy, painless insomnia, mayTherebe fever, headache, intense in T. fly bite infection).(rare b. tsetse gambiense site of the primary at the nodular) or (papular chancre involvement).painful is a There (haemolymphatic stage First description Clinical definition Case continent. of the areas south-eastern and eastern the in found ally (acute T. form) gener is b. rhodesiense of Africa. parts south-western and central western, the in found T. generally is (chronic disease) b. untreated. gambiense and Communicable disease epidemiological profile epidemiological disease Communicable

compatible with the clinical description. clinical the with compatible or not whether theparasite, of demonstration direct with case a Confirmed: background. historical disease on local and disease the of contracting risk on local based then Suspicion is disease. the with associated classically or symptoms signs clinical no often are there disease, of the stage second the in or early stage first the serology. In positive and/or with description clinical the with patible com is that parasite of the demonstration direct without case any Suspected:

no detectable trypanosomes and a leukocyte count ≤ 5/µl. ≤5/µl. count a leukocyte and trypanosomes no detectable containing CSF with nodes, and/or blood lymph in seen parasite stage: First . - - 19

Second stage: parasite seen in blood and/or lymph nodes, with CSF containing trypanosomes and/or a leukocyte count > 5/µl.

Mode of transmission The disease is transmitted primarily by the bites of infected tsetse fliesGlossina ( spp.). Transmission is also possible through contamination with infected blood or through the placenta (congenital).

Incubation period T. b. gambiense infection has a long incubation period that may last several months or even years. T. b. rhodesiense infections progress rapidly and are more virulent, with a short incubation period lasting from 3 days to a few weeks.

Communicability period The disease is communicable to the tsetse fly as long as the parasite is present in the blood of the infected person or animal reservoir (5–21 days after the infective bite). Parasitaemia occurs in waves of varying intensity in untreated cases during all stages of the disease. Once infected, the tsetse fly remains infective for life (1–6 months). AFRICAN TRYPANOSOMIASIS (SLEEPING SICKNESS) (SLEEPING TRYPANOSOMIASIS AFRICAN Epidemiology General T. b. gambiense, human African trypanosomiasis, which causes the chronic form I of this disease, is endemic in CAR and Chad and is a neglected tropical disease. An important feature of African trypanosomiasis is its focal nature: it tends to occur in circumscribed zones, and observed prevalence levels vary greatly from one geographical area to another, and even between one village and another II within the same area. African trypanosomiasis also affects cattle. Expansion of animal trypanosomiasis into new areas may lead to massive outmigrations and abandonment of settlements. Long-distance migration increases periods of stress resulting from trekking, which III render cattle more susceptible to infection. In general, countries are placed in four categories in terms of prevalence; those that report no cases, <50 cases, 50 to 1000 cases, >1000cases. Both Chad and CAR are classed by WHO as being countries which report 50–1000 cases per year. in IV each country, the spatial distribution of the diseases is very diverse; it is found in both macro- and micro- foci.

Communicable disease epidemiological profile 20 CENTRAL AFRICAN REPUBLIC AND CHAD tat, thereby reducing fly density and subsequently reducing the risk of transmission. of risk the reducing andsubsequently density fly reducing thereby tat, animals used for preparing land for crops. land for preparing used animals draught of efficiency and the availability reduces disease The expansion. tural for agricul potential continent’s greatest holdsthe which zone, semi-arid of the parts and zonewetter thesub-humid in serious is most risk The countries. African in 37 cattle million 50 estimated an threatens disease the of form animal The screening. provide can that centre health to a or access examination regular with surveillance, under are million 3–4 only of which Africa, of sub-Saharan countries 36 in people million >60 threatens ness sick S. Sleeping 20° and 15° N between Africa tropical to confined is disease The distribution Geographical disease. this suspect strongly should foci disease known are wherethere areas rural from coming populations of IDPs or refugee charge in officers medical symptoms, neurological chronic with patients encountering When Communicable disease epidemiological profile epidemiological disease Communicable long asymptomatic avery has which sickness sleeping for gambiense ticularly services health to access Poor Population movement Risk factors for increased burden Overcrowding. areas. endemic into placed dis are or populations when area atsetse-infested into strains virulent introduce hosts reservoir when intensified, is contact human–fly when occur Outbreaks Epidemics rhodesiense. of T. b. reservoirs main the are antelopes, and bushbucks especially animals, wild and cattle Domestic of T. infection. major b. reservoir gambiense the are Humans Reservoirs farmers. sedentary with conflict in may result this and patterns grazing for implications have flies of tsetse density the in fluctuations Seasonal pattern. seasonal obvious clearly no has disease The Seasonality

An increased density of the human population destroys tsetse habi tsetse destroys population human of the density increased An . Risk is associated with settlement in a high-transmission area. area. a high-transmission in settlement with is associated Risk Systematic population screening is necessary, par necessary, is screening population . Systematic -

- - - - 21 period. The complex nature of the disease and inadequate control tools require efficient health structures and trained personnel for diagnosis and treatment. Food shortages. These result in people entering the forest and rivers for food, fishing and hunting, thereby increasing human–fly contact and the risk of contracting the infection. Lack of safe water and poor sanitation. The tsetse fly is not attracted by dirty water. However, lack of water supply in villages forces people to search for water in tsetse habitats, increasing the risk of infection.

Prevention and control measures Case management Early screening and diagnosis are essential, as treatment is easier during the first stage of the disease (the patient does not present with psychiatric symptoms, fewer injections are required, and treatment poses less risk to the patient and may be given on an outpatient basis). Diagnosis and treatment require trained personnel; self-treatment is not possible.

All confirmed cases must be treated as soon as possible. Most available drugs SICKNESS) (SLEEPING TRYPANOSOMIASIS AFRICAN have been in use for many years, are difficult to administer in poor conditions, and frequently unsuccessful. T. b. gambiense infection: I

First stage: pentamidine – 4 mg/kg per day intramuscularly (IM) for 7 consecutive days on an outpatient basis. Second stage: II eflornithine: hospitalization, with 400 mg/kg administered in slow infusions (lasting approximately 2 hours) four times a day. Infusions of 100mg/kg are given every 6 hours for 14 days. melarsoprol – hospitalization, with injections of 2.2 mg/kg/day adminis- III tered intravenously (IV) for 10 consecutive days. In case of treatment failure with one drug, the other should be used.

T. b. rhodesiense infection: IV

First stage (early stages of the disease): suramin IM, 20mg/kg per week for 5 weeks.

Communicable disease epidemiological profile 22 CENTRAL AFRICAN REPUBLIC AND CHAD sleeping sickness. Active periodical screening screening periodical Active sickness. for control T. sleeping ease b. gambiense of dis cornerstone the remain of cases chemotherapy and screening population periodical through reservoirs human of the containment and detection Case 2011. until needs global meet to aresufficient eflornithine and melarsoprol suramin, of pentamidine, to WHO donations Drug charges. customs and costs transport pay, the only possible, when recipient countries of charge: free provided are drugs the All guidelines. WHO frontières sans Médecins governments. these with association in working organizations and countries of disease-endemic by governments to WHO made are supplies forWHO. are to donated Requests drugs The available. widely drugs all made has by WHO signed 2001, partnership Since apublic–private procurement. Drug of resistance. (4) and schedules; surveillance treatment and on resistance (3) research trials; development clinical and (2) of drug coordination accessibility; and (1) with: availability deal groups drug working Four network. resistance drug and treatment trypanosomiasis African ahuman established has WHO conditions. field under administer to 6difficult hours)is every IV (slow 100mg/kg Eflornithine possible. if units care intensive in and settings hospital in administered be must drug The Angola. northern and Uganda northern in foci and Congo of the Republic Democratic the in provinces Equateur and Kasai Sudan, southern in foci T.b.gambiense in some 25%)areas as in (asmelarsoprol high reported have been to of resistance rates Increasing cases. of the half about outcome in afatal with 5–10% in of patients, encephalopathy reactive causes Melarsoprol comments. General Communicable disease epidemiological profile epidemiological disease Communicable encouraged: be should following on the education public through preventive measures Routine Prevention

routine use of insect repellents and mosquito nets. nets. mosquito and repellents of insect use routine areas; endemic long trousers)in and long sleeves (including clothing suitable wearing infestation; and/or tsetse sickness of sleeping foci of known avoidance days. for 10 IV consecutive administered day per mg/kg of 2.2 injections with –hospitalization, melarsoprol stage: Second undertakes stock control and delivery of the drugs in accordance with with accordance in drugs of the delivery and control stock undertakes -

(active case-finding) of the population of endemic foci by mobile screening teams is the best option, since infected subjects may remain asymptomatic and contagious for months or years before developing overt symptoms. Screening usually comprises CATTs of the entire population visited by teams. Vector control through tsetse-fly control programmes:

application of insecticides or aerosol insecticides; use of insecticide-impregnated traps and screens.

Destruction of tsetse habitats by selective clearing of vegetation: clearing bushes and tall grasses around villages is useful when peridomestic transmission occurs. Indiscriminate destruction of vegetation is not recommended.

Epidemic control T.b.gambiense. see Prevention above. T. b. rhodesiense. Where epidemics are caused by T.b. rhodesiense, active screening using parasitological methods and vector-control measures is appropriate. Mass treatment of cattle provides an additional benefit for effective control. All identified

cases must be promptly treated. Tsetse-fly control measures (e.g. aerosol insecticides SICKNESS) (SLEEPING TRYPANOSOMIASIS AFRICAN sprayed by helicopter and fixed-wing aircraft) should be implemented urgently.

III

Communicable disease epidemiological profile 24 CENTRAL AFRICAN REPUBLIC AND CHAD No information available. No information Chad 6.9%). (379 CFR prefecture cases, Ouham-Pendè in 2003 June–October during occurred to ciprofloxacin 1sensitive type dysenteriae of Shigella Outbreaks Central African Republic Country-specific disease burden (shigellosis) dysentery Bacillary Communicable disease epidemiological profile epidemiological disease Communicable andmaybe up to one Sd1. for week 1–3days, usually is period incubation The Incubation period meals. of contaminated source acommon are stalls Food organism. the transmit may also organisms). Flies low is very (10–100in humans microbes of dose infectious The food. and water contaminated through route, particularly faecal–oral the through It transmitted is Mode of transmission classification Case definition Case level. be regional ata even and may significant often are that demics for responsible epi usually is and 1(Sd1) disease severe most the serotype causes dysenteriae Shigella countries, developing in shigellosis of endemic cause chief the is flexneri S. Although illness. mild relatively cause usually boydii S. and sonnei S. serotypes. into subdivided further is serogroup Each Drespectively. Cand B, A, ( species four includes which the Shigella genus of agentbacterium is a infectious The Infectious agent Description S. flexneri ,S. dysenteriae S.

from stools. from of Shigella isolation with definition, case thesuspected to corresponding case a case: Confirmed stools. the in blood visible with diarrhoea case: Suspected S. Sonnei) S. and boydii , S. , also designated as serogroups serogroups as designated , also

- 25

Communicability period During acute infection and up to four weeks after illness (without treatment); 2–3 days with appropriate treatment. Asymptomatic carriers exist.

Epidemiology General Globally, shigellosis is estimated to cause 80 million cases of bloody diarrhoea and 700 000 deaths per year. 99% of cases occur in developing countries; 70% of cases and 60% of deaths occur in children under 5 years of age. Illness in infants under 6 months is unusual. In endemic areas, the disease is more severe in young children than in adults, among whom many infections may be asymptomatic. The elderly, the weak and the malnourished of all ages are particularly susceptible to severe disease and death. Early detection of cases and use of antibiotic therapy are essential.

Geographical distribution Worldwide, shigellosis is endemic in both temperate and tropical climates. Multidrug-resistant Shigella with considerable geographical variations have

appeared worldwide in relation to the widespread use of antimicrobial agents. (SHIGELLOSIS) DYSENTERY BACILLARY

Seasonality No data available. I Alert threshold In the absence of a clear epidemic threshold, an epidemic should be suspected if:

there is an unusual and sudden rise in the number of new cases or deaths due II to bloody diarrhoea reported weekly; there is an increase in the proportion of bloody diarrhoea among diarrhoeal cases; there are five or more linked cases of bloody diarrhoea. III Any of the above scenarios should lead to investigation of the disease agent by laboratory testing.

Epidemics IV Susceptibility is general. Secondary attack rates in households can be as high as 40%. Outbreaks may occur in crowded conditions where sanitation facilities are

Communicable disease epidemiological profile 26 CENTRAL AFRICAN REPUBLIC AND CHAD especially at food stalls. at food especially Other risk factors risk Other affected). may be at risk population the of third (up to one settings camp in high Sd1is of epidemics of risk factor. The sanitation poor and water safe of Lack illness. during children and infants breastfeeding to continue important therefore it is and children, young and infants protects Breastfeeding of disease. severity and organism of the siveness shortages Food mount transmission. to reduce or hyperthermia, or presents with a history of convulsions. ahistory with or presents or hyperthermia, hypo- unconsciousness, dehydration, develops who patient or any malnourished the measles, from recovering children not breastfed, children years, >50 adults in and infants in seen be to likely are death of risk greater and disease severe 15%. as More high as may be However, fatality hospital. in case treatment require to insufficient is illness <1% whose to be those among estimated is fatality Case food. contaminating pathogens of faecal risk the increases This prisons. and hospitals psychiatric centres, day-care children, for institutions camps, refugee poor, in is hygiene as such personal and lacking Communicable disease epidemiological profile epidemiological disease Communicable of susceptibility antibiotic the to confirm It important therefore is Africa. in Sd1 treatment the aproblem is in resistance of antimicrobial acquisition Rapid availability. on drug and bacteria of the patterns on resistance depends Selection of shigellosis. duration and severity may the reduce microbial anti effective an with treatment important; very is appropriate therapy and Early Casemanagement Prevention and control measures services health to access Poor affected). may be at risk population (up of the to one third settings camp in Overcrowding agent. infectious of the transmission increases movement Population Risk factors for increased burden increases the risk of infection. The risk of epidemics of Sd1 is high high Sd1is of epidemics of risk The of infection. risk the increases Malnutrition increases gastrointestinal tract susceptibility to inva susceptibility tract gastrointestinal increases . Malnutrition Poor hygiene and lack of soap may lead to contaminated food, food, to contaminated may oflead soap lack . Poor and hygiene Early detection and containment of cases are para are of cases containment and detection . Early These represent a highly significant risk risk significant highly a represent . These

- - -

S. dysenteriae not only in the early stages of an outbreak but also to confirm the resistance patterns during the course of an outbreak, through the taking of regular stool samples, as patterns may vary. Ciprofloxacin is the current first-line antibiotic of choice recommended for treatment of Sd1. There is no available antibiotic resistance data for CAR or Chad.

Recommendations for treatment of Shigella dysenteriae type 1a

Patient group/ Dose Dosing frequency Duration of treatment treatment

Adults: ciprofloxacin 500 mg Twice a day 3 days

Children: ciprofloxacin 250 mg/15 kg body weight Twice a day 3 days

For children aged less than 10 mg Daily 2 weeks 6 months: add zinc

For children aged 6 months 20 mg Daily 2 weeks to 3 years: add zinc a Rapidly-evolving antimicrobial resistance is a serious problem. Sd1 is usually resistant to ampicillin and trimethoprim−sulfamethoxazole (TMP–SMX). BACILLARY DYSENTERY (SHIGELLOSIS) DYSENTERY BACILLARY Supportive treatment using oral rehydration salts (ORS), continued feeding (frequent small meals) and antipyretics to reduce high fever are also essential. More detailed advice on how to rehydrate and how to feed a child during a diarrhoeal I disease episode is given in The treatment of diarrhoea, A manual for physicians and other senior health workers. Details of this and other sources of further information are given in the reference list below, and under Child health in emergencies in Annex 3. II Sd1 is often more severe or fatal in young children, the elderly and malnourished individuals; prompt treatment with antibiotics is essential. If in short supply, antibiotics should be reserved for such high-risk groups. Breastfeeding is protective to infants and young children. It is therefore important III to continue breastfeeding infants and children during the illness.

Prevention Information may be found in the section on Diarrhoeal diseases in this document, IV under Prevention; in Annex 4 under Water, sanitation and health, and in references (2) and (3) under Further reading.

Communicable disease epidemiological profile 28 CENTRAL AFRICAN REPUBLIC AND CHAD curtailing transmission. transmission. curtailing of means asa defecation after water and soap with hand-washing of effectiveness and importance told be the must Patients orcare. patient child or to provide food not employed be should to handle infections Shigella known with Patients activities. treatment/control starting before results waitlaboratory not for Do pattern. resistance antimicrobial the of confirmation and the organism of identification the in to assist available are laboratories referral tional Interna appropriate. remain guidelines treatment whether to determine intervals done be at regular should susceptibility for antimicrobial Testing of isolates Sd1 patient. every for confirmation laboratory to obtain sary is not it neces confirmed, is outbreak the Once 6hours. within processed be and laboratory the reach must sample but the not is available, medium Cary-Blair if sent may be samples stool Fresh susceptibility. antibiotic and strain pathogen the the outbreak, to confirm used are 10–20 samples that It recommended therefore is unreliable. findings analysis laboratory and 1–3 variable for very is between days when refrigerated medium this in bacteria of viability The 2hours. within lysed ana be should specimen the Sd1. of Ideally, diagnosis the to confirm for culture (e.g. appropriate medium Cary-Blair) an in °C) to alaboratory (0–4 acold chain in shipped immediately and collected be should cases suspected from swabs Rectal guidelines. WHO following confirmed be should The outbreak control. and management for appropriate case needed of resources mobilization timely allow amongadults, especially dysentery, epidemic of notification and detection Early identified. are cases one or more if suspected informed be should authorities Health Epidemiccontrol Communicable disease epidemiological profile epidemiological disease Communicable 5. 4. 3. 2. 1. reading Further Emerging issues in water and infectious disease disease infectious and in water issues Emerging 1; www.who.int/cholera/publications/first_steps/en/index.html). Rev (WHO/CDS/CSR/NCS/2003.7 diarrhoea acute of outbreak an managing for steps First (www.who.int/topics/cholera/publications/critical_steps/en/index.html). 2004 Organization, World Health Geneva, steps. critical emergencies: complex in diseases diarrhoeal Acute en/index.html). (www.who.int/topics/cholera/publications/shigellosis/ 2005 Organization, World Health Geneva, 1 type dysenteriae Shigella to due epidemics including shigellosis, of control the for Guidelines 9241593180/en/). (www.who.int/entity/child_adolescent_health/documents/ 2005 Organization, World Health Geneva, workers. health senior other and physicians for manual a diarrhoea: of treatment The (www.who.int/water_sanitation_health/emerging/en/). . Geneva, World Health Organization, 2003

- - . - 29 CHOLERA

Country-specific disease burden Central African Republic No information available.

Chad Recent outbreaks:

June–December 2006 (1633 cases, 68 deaths, CFR 4.1%). Areas affected: Karassoua Moussari (Hadjer Lamis), Bol district (islands of Lake Chad), N’Djamena and Kanem regions. June–September 2004 (3910 cases, CFR 4.2%). Areas affected: Bousso, Massaguet (Hadjar Lamine), Lac, Kanem, N’Djamena, Mongo and Ati. July–September 2001 (3557 cases, CFR 3.2%,). Areas affected: south-western part of the country (N’Djamena, Massakory, Bongo, Bol). CHOLERA

Description Infectious agent I The bacterium Vibrio cholerae O1 and O139.

Case definition Clinical case : a person aged > 5 years that develops severe dehydration or dies II from acute watery diarrhoea. Suspected case: that corresponds to the clinical case definition. Confirmed case: isolation of Vibrio cholerae O1 or O139 from stools in any patient III with diarrhoea.

Mode of transmission Mainly faecal–oral route: IV drinking contaminated water, including accidental ingestion of contaminated surface water;

Communicable disease epidemiological profile 30 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable outbreaks. major to detect enough order sensitive to be in strengthened be should systems surveillance Disease mortality. associated reducing for successfully factor key the is preparedness overcrowded in settings, high is of outbreaks cholera risk the As <1% outbreaks. be should rates during case-fatality cholera properly managed, is kits disease (see diarrhoeal below Interagency areas high-risk in outbreak of emergence an before the prepared be should units treatment Cholera assured. be cannot sanitation adequate and drinking-water to safe whereaccess and infrastructure health no basic is there where slums peri-urban for are cholera Typical settings annually. have occurred and outbreaks thesubregion in problem health public asignificant is Cholera General Epidemiology common. are carriers Asymptomatic months. recovery. 2–3after rarely, days forVery until phase symptomatic the During period Communicability days. to 5 a hours few usually is period incubation The Incubation period

Indirect contamination (hands): poor hygiene and lack of soap. lack and hygiene poor (hands): contamination Indirect Person to person: brackish water as a result of occupational accidents among fishermen. among accidents of occupational aresult as water brackish in especially exposure, environmental from arise may infections Wound

may play a major role in the spread of spread epidemics. may play the amajor role in ariver, in deceased of the bodies placing as such practices, some cultural ceremonies); for funeral body the washing (e.g. patients cholera deceased from bodies with contact direct through when taking care of patients; cholera care taking when seafood. contaminated vendors), street from food or (rice, millet, preparation or during hands water, dirty soil, through vegetables) and contaminated (fruits food eating ). When the disease disease the ). When 31

Geographical distribution Cholera is endemic in CAR and Chad.

Seasonality Cases are distributed mainly during the wet season starting in July–August. Climate fluctuations related to warming of oceans, such as El Niño, may be associated with an increase in cholera cases.

Alert threshold Any suspected case must be investigated. A cholera outbreak should be suspected if: a person aged > 5 years develops severe dehydration or dies from acute watery diarrhoea (clinical case definition); or there is a sudden increase in the daily number of patients with acute watery diarrhoea, especially patients who pass the “rice water” stools typical of cholera.

Risk factors for increased burden Population movement plays an important role in the transmission of the infectious agent. CHOLERA Overcrowding increases the risk of contact with the bacterium contained in vomitus, excreta and contaminated water or food. I Poor access to health services. Early detection and containment of cases (isolation facilities) are paramount in reducing transmission. Food shortages. In the context of food shortage, nutritional status is a determinant of the severity of diarrhoea in patients with cholera. Malnutrition enhances the II risk of diarrhoeal illness, which in turn produces more profound malnutrition. Prolonged diarrhoea in malnourished patients may result in a significant increase in the need for fluids, electrolytes and nursing capacity. Lack of safe water and poor sanitation are the main risk factors. III

Prevention and control measures Case management IV The mainstay of the case management of cholera is the treatment of dehydration using ORS or IV fluids (Ringer’s lactate). IV rehydration should be used for severe cases only.

Communicable disease epidemiological profile 32 CENTRAL AFRICAN REPUBLIC AND CHAD below.) kits disease < 1%. be should diarrhoeal CFR (See Interagency the management, case priate appro With treatment. without proper high (5–40%) extremely be can CFR The 3 Annex in emergencies in health Child below). also See (see reference workers ( health senior other and physicians for amanual diarrhoea, Thetreatment in given are of of diarrhoea treatment during on how achild to feed Recommendations to fed preventcontinuously malnutrition. be should patient The appropriate antibiotic. the order to select in assessed be should pattern susceptibility antimicrobial The excretion. cholerae Vibrio of period the and duration its to shorten and required), solutions rehydration (and of the volume of diarrhoea the to reduce cases severe in but used may be treatment for disease not is essential (doxycycline/tetracycline) Use of antibiotics Communicable disease epidemiological profile epidemiological disease Communicable 5 of outbreaks. control cholera prevention and on guidelines WHO following be confirmed should The outbreak identified. are cases one or more if suspected immediately informed be should authorities Health Epidemiccontrol activities. control and management case starting before results waitlaboratory not for Do patient. every for confirmation laboratory to obtain is notit necessary confirmed, Once susceptibility. antibiotic identify and the outbreak to confirm used are 10 at least cases that It recommended is laboratory. to the sent and sealed tightly bag, plastic asterile in placed stool, liquid the in soaked be may swab rectal acotton-tipped not is available, medium atransport If medium. Cary-Blair in transported and swab arectal with taken be should samples Stool

Set up ORS corners to increase the population’s access to oral rehydration. to oral population’s the access to increase corners up ORS Set education. health adequate Provide centres. treatment cholera in cases severe Isolate diagnosis. the confirm and management prompt case Ensure Media/PDF/cholera_whopolicy.pdf. www.emro.who.int/CSR/ www.who.int/cholera/publications/cholera_outbreak/en/index.html; at Available 5

4 - ) 33

Ensure access to safe water and proper sanitation. Ensure hand-washing with soap. Ensure safe food handling.

Interagency diarrhoeal disease kits (which contain four separate modules) may be obtained for preparedness or response. It is advisable to have complete kits for preparedness, but each module may be ordered separately according to the availability of components locally. Information regarding the content of these kits may be found below in the reference list. The shelf-life of all components of the kit is a minimum of three years. No cold chain is required.6

Prevention Information may be found in the section on Diarrhoeal diseases below, under Prevention; in Annex 4 under Water, sanitation and health, and in references (2) and (7) below.

Immunization CHOLERA Implementation of normal prevention and control measures, including the improvement of water and sanitation, remains the foundation of outbreak prevention and response. The use of oral cholera vaccine (OCV) is considered to be a public health tool additional to the normal recommended cholera prevention and control meas- I ures, especially when given pre-emptively if the population at risk can be accurately identified. Currently there is only one WHO prequalified oral cholera vaccine, killed whole-cell V. cholerae O1 recombinant B-subunit of cholera toxoid (WC/rBS), available for use in public health. II The relevance of OCVs should be assessed by using the WHO decision-making tool on a case-by-case basis (see reference (3) below). Earlier parenteral cholera vaccine should not be used and has never been recommended by WHO. III For more specific information on cholera vaccines and their use, please contact the Global Task Force on Cholera Control at WHO headquarters.7

6 These kits or modules may be purchased by non-WHO agencies through MEG, the Medical Export Group BV, Gorinchem, Netherlands ([email protected] and www.meg.nl) or by WHO through a usual requisition IV (product “kit and modules” are available in the WHO catalogues under “kits”). 7 [email protected].

Communicable disease epidemiological profile 34 CENTRAL AFRICAN REPUBLIC AND CHAD 9. 8. 7. 6. 5. 4. 3. 2. 1. References Communicable disease epidemiological profile epidemiological disease Communicable

emro.who.int/CSR/Media/PDF/cholera_whopolicy.pdf). (http://www. recommendations and policy – WHO outbreaks of cholera control and Prevention cholera/complete.pdf). http://www.cdc.gov/ncidod/dbmd/diseaseinfo/ (WHO/CDS/CSR/EDC/99.8; 1999 Organization, cholera and dysentery epidemic of diagnosis the for methods Laboratory critical_steps/en/) http://www.who.int/topics/cholera/publications/ (WHO/CDS/CPE/ZFK/2004.6; 2004 tion, steps critical emergencies: complex in diseases diarrhoeal Acute cholera/publications/cholera_outbreak/en/index.html). http://www.who.int/topics/ (WHO/CDS/CPE/ZFK/2004.4; 2004 Organization, World Health preparedness improving and response outbreak the assessing outbreak: Cholera first_steps/en/index.html). Rev1; http://www.who.int/topics/cholera/publications/ (WHO/CDS/CSR/NCS/2003.7 2004 diarrhoea acute of outbreak an managing for steps First documents/9241593180/en/). (http://www.who.int/entity/child_adolescent_health/ 2005 Organization, World Health Geneva, workers. health senior other and physicians for manual a diarrhoea: of treatment The cholera/publications/cholera_vaccines_emergencies_2005.pdf). http://www.who.int/topics/ (WHO/CDS/NTD/IDM/2006.2; 2006 Organization, World Health Geneva, 2005. December Cairo, next? what emergencies: complex in use vaccine cholera Oral DiarrhoealDiseaseKits/en/index.html). (http://www.who.int/topics/cholera/materials/en/;2006 http://www.who.int/cholera/technical/ note -information kits disease diarrhoeal Interagency who.int/wer/2008/wer8331.pdf). 2007. report Choleraannual WeeklyRecord Epidemiological . Geneva, World Health Organization, Organization, World Health . Geneva, . Geneva, World Health Organization, Organization, World Health . Geneva, , 2008, 83(31):269–284 (http://www. 2008, , . Geneva, World Health Organiza World Health . Geneva, . Geneva, .World Geneva, Health . Geneva, . Geneva, 35 DIARRHOEAL DISEASES (OTHERS)

Country-specific disease burden Central African Republic Country-specific data are not available.

Chad Country-specific data are not available.

Description Infectious agent Bacteria: the bacteria that cause the most severe outbreaks are Shigella dysenteriae type 1 and Vibrio cholerae (see Bacillary dysentery and Cholera above). Salmonella spp. (commonly S. enteritidis, S. typhimurium) and a small number of strains of Escherichia coli may also cause disease. Protozoa: e.g. Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. DIARRHOEALDISEASES (OTHERS) Viruses: e.g. rotavirus and Norwalk virus.

Case definition Three or more abnormally loose or fluid stools over a period of 24 hours. I

Mode of transmission Faecal–oral route, particularly contaminated water and food. II Incubation period Salmonella generally require an 8–48 hour incubation period, whereas E. coli typically require longer, with 2–8 days (median 3–4 days). The duration of the disease in both cases is usually 2–5 days. The average incubation period is 2–4 weeks for E. histolytica, 7–10 days for G. lamblia and 7 days for C. parvum. The III incubation period for rotavirus is about 48 hours; it mainly affects children aged < 5 years and symptoms may last for up to 1 week. Communicability period IV During the acute stage of the disease and for the duration of faecal excretion. Temporary Salmonella carriers may continue to exist for several months.

Communicable disease epidemiological profile 36 CENTRAL AFRICAN REPUBLIC AND CHAD sanitation poor and water safe of Lack infection. extra-intestinal serious cause and malnutrition in result or longerturn may in 14 days lasting Persistent diarrhoea of disease. severity and of some organisms ness shortages. Food transmission. reducing mount in Seasonality but endemic. available, No data distribution Geographical <2years. aged children among are of deaths 80% emergency. of the More phase than acute the in of deaths 25% 40% and for between have accounted diseases diarrhoeal situations, camp In General Epidemiology Communicable disease epidemiological profile epidemiological disease Communicable services health to access Poor Overcrowding Population movement Risk factors for increased burden area. adefined in years previous in period same the with compared number expected above the of cases number the in increase An thresholdAlert risk. Year-round and exposure Common sources of infection in emergency situations are: situations emergency in of infection sources Common day. per litres/person 20 is requirement emergency minimal The priorities. est high one be of the should population to ofthe water quantities supply of adequate The safety. food for and proper education hygiene health and sanitation adequate water, of safe use and provision on the depends diseases of diarrhoeal Prevention

shared water containers and cooking pots. pots. cooking and containers water shared by faeces); soiled hands with contact (e.g. storage by during orcontaminated well) water sealed incompletely an ing enter water surface (e.g. sources by water faecally-contaminated contaminated facilitates transmission. transmission. facilitates Malnutrition increases gastrointestinal tract susceptibility to invasive susceptibility tract gastrointestinal increases Malnutrition

may facilitate transmission of the pathogen and importations. importations. and pathogen of the transmission mayfacilitate Early detection and containment of cases are para are of cases containment and detection . Early are the most important risk factors. factors. risk important most the are

- - - - 37 Prevention and control measures Case management Reduction of mortality caused by diarrhoeal disease is primarily related to effective management of dehydration, particularly in children.

Prevention: give recommended home fluid and ORS. Treatment of dehydration – with ORS for mild to moderate dehydration, or with IV fluids (Ringer’s lactate) for severe dehydration – is the mainstay of the management of diarrhoeal illness. Use of antibiotics depends on the infectious agent. Resume feeding with a normal diet when vomiting has stopped. It is important to separate those who are eating from those who are not. Food should be cooked on site. Continue breastfeeding of infants and young children.

Epidemic control Health authorities should be informed immediately if an increase in the number of cases above the expected number is identified. The outbreak should be confirmed following WHO guidelines. Proper case management and epidemic control activities should be ensured. DIARRHOEALDISEASES (OTHERS) Prevention The prevention of diarrhoeal diseases depends on the provision and use of safe water, adequate sanitation and health education. I Safe drinking-water Provision of an adequate and safe supply, collection and storage system. Provision of information on the importance of clean water and appropriate household storage of water (see Water, sanitation and health in Annex 4). II

Safe disposal of human excreta Provision of adequate facilities for the disposal of human waste. Provision of information on the importance of human waste disposal, use of III sanitation covers and correct maintenance of sanitation facilities.

Food safety Provision of adequate food storage facilities (for both uncooked and cooked IV food), cooking utensils, adequate quantities of water and fuel to allow for cooking and reheating.

Communicable disease epidemiological profile 38 CENTRAL AFRICAN REPUBLIC AND CHAD Breastfeeding soap with Hand-washing Communicable disease epidemiological profile epidemiological disease Communicable 4. 3. 2. 1. References

Practical support for breastfeeding ill children. children. ill for breastfeeding support Practical children. ill of breastfeeding importance the and of breastfeeding qualities protective on the of information Provision children. cleaning/changing after and before preparation food toileting, after before eating, hand-washing poor of or lack and spread disease between relationship on the education Health needs. dry and laun bathing hand-washing, for quantities sufficient in of soap Provision food-handling. safe and safety of food importance on the education Health cholera/complete.pdf). www.cdc.gov/ncidod/dbmd/diseaseinfo/ (WHO/CDS/CSR/EDC/99.8; 1999 Organization, World Health Geneva, cholera. and dysentery epidemic of diagnosis the for methods Laboratory steps/en/index.html). Rev1; www.who.int/topics/cholera/publications/first_ (WHO/CDS/CSR/NCS/2003.7 2003 Organization, World Health Geneva, diarrhoea. acute of outbreak an managing for steps First steps/en/index.html). www.who.int/topics/cholera/publications/critical_ (WHO/CDS/CPE/ZFK/2004.6; 2004 tion, Organiza World Health Geneva, steps. critical emergencies: complex in diseases diarrhoeal Acute Publications/CHILD_HEALTH/ISBN_92_4_159318_0.pdf). health/New_ (www.who.int/child-adolescent- 2005 Organization, World Health rev. Geneva, Fourth workers. health senior other and physicians for manual a diarrhoea: of treatment The - 39 DIPHTHERIA

Country-specific disease burden Central African Republic Zero cases were reported to WHO for 2007, as of 1 July 2008.8

Chad No report was made to WHO for 1999–2007, as of 1 July 2008.

Description Infectious agent The bacterium Corynebacterium diphtheriae.

Case definition Upper respiratory tract illness with laryngitis or pharyngitis or tonsillitis plus adherent greyish membranes on tonsils and/or nasopharynx. DIPHTHERIA

Clinical description Diphtheria is an acute toxin-mediated disease caused by toxigenic strains of Corynebacterium diphtheriae. The disease affects the mucous membranes of the I respiratory tract (respiratory diphtheria), the skin (cutaneous diphtheria), and occasionally mucous membranes at other sites (eyes, ears or vagina). Cutaneous and nasal diphtheria are localized infections that are rarely associated with systemic toxicity. II Symptoms of respiratory diphtheria have a gradual onset and include malaise, sore throat, difficulty swallowing, loss of appetite and a mild fever (rarely > 38° C), with laryngeal involvement and hoarseness. Within 2–3 days, a firmly adherent, grey membrane forms over the mucous membrane of the tonsils, pharynx or both. III In severe cases, cervical lymphadenopathy and soft tissue swelling in the neck give rise to a “bull-neck” appearance. Extensive membrane formation may result in life-threatening or fatal airway obstruction. Diphtheria toxin may cause serious life-threatening systemic complications, including myocarditis and neuropathies. IV

8 www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencedip.htm.

Communicable disease epidemiological profile 40 CENTRAL AFRICAN REPUBLIC AND CHAD or confirmed cases. or confirmed probable as not reported be should carriers) (i.e. asymptomatic description ical clin the who do not meet identification diphtheriae C. positive PeopleNote. with Case classification Case specimen. aclinical from diphtheriae of C. Isolation confirmation Laboratory treatment. of 5–10%, rate with even acase-fatality with gency emer amedical is persons, unimmunized in particularly diphtheria, Respiratory Communicable disease epidemiological profile epidemiological disease Communicable 9 of outbreaks. risk the increases (EPI) diseases on Immunization Programme (< coverage 80%) vaccination Low Expanded at 79%. for routine estimated is coverage global and Chad, in 40% and CAR in 20% as reported is coverage DPT3 General Epidemiology given. are antibiotics after 48 hours contagious not usually is disease or more. The for months 6 diphtheriae C. may shed carrier chronic rare The 4weeks. seldom more than and or less 2 weeks usually lesions; and discharges from have disappeared diphtheriae C. viable Until period Communicability longer. occasionally 2–5 days, Usually Incubation period as a vehicle). served has milk (raw foodstuffs through transmitted may be disease the (uncommon). fomites and cases, lesions, rare In skin from discharge or carrier, acase from droplets respiratory the with indirect) rarely direct, (usually Contact Mode of transmission

in nasopharynx, without symptoms. without nasopharynx, in diphtheriae of C. presence Carrier: case. to alaboratory-confirmed linked or by alaboratory case: epidemiologically confirmed probable case Confirmed description. clinical the meets that acase case: Probable http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencedip.htm. 9

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Outbreaks may occur when toxigenic C. diphtheriae is introduced into populations with low herd immunity (poor DTP3 coverage in children; low natural boosting or diphtheria toxoid booster coverage in adolescents and adults), especially when social or natural conditions lead to overcrowding of susceptible groups. This frequently occurs when there are large-scale movements of non-immunized populations.

Geographical distribution Throughout CAR and Chad.

Alert threshold Any probable case must be investigated.

Recent epidemics None recorded.

Risk factors for increased burden Population movement allows importation and facilitates transmission. Overcrowding facilitates transmission. DIPHTHERIA Poor access to health services prevents access to routine immunization services resulting in low herd immunity. Early detection and containment of cases reduce transmission. I Lack of safe water and poor sanitation promote cutaneous diphtheria spread (in conjunction with crowding).

Prevention and control measures II The control of diphtheria is based on three measures:

ensuring high population immunity through vaccination (primary prevention); rapid investigation and treatment of contacts (secondary prevention of spread); III early diagnosis and proper case management (tertiary prevention of complications and deaths).

Case management IV Diphtheria antitoxin is the cornerstone of therapy for respiratory diphtheria. The antitoxin neutralizes the diphtheria toxin only before its entry into cells. It is

Communicable disease epidemiological profile 42 CENTRAL AFRICAN REPUBLIC AND CHAD Antibiotic treatment should be continued for a total period of 14 period days. for atotal continued be should treatment Antibiotic activities. treatment/control before starting results for laboratory notDo wait plus: In addition, antibiotic therapy, by killing the organism, has three benefits: three has organism, the therapy, by killing antibiotic addition, In reactions. anaphylactic fatal to avoid potentially before administration mandatory is sitivity Testing for hypersen patient preparation. serum equine an is antitoxin Diphtheria Note made. been has diagnosis tive apresump as soon as administered be antitoxin diphtheria that critical therefore Communicable disease epidemiological profile epidemiological disease Communicable 11 10 Isolation Patients

cautions must be observed in order to prevent contact with cutaneous lesions. lesions. cutaneous order with to prevent in contact observed be must cautions However, pre not is necessary. barrier isolation strict diphtheria: Cutaneous necessary. is isolation strict diphtheria: Pharyngeal doses. of 2g/day) divided four in amaximum with day per mg/kg (40–50 erythromycin V(125–250 aday) or oral times four mg penicillin oral then swallow; can patient the of 2g/day) until to amaximum day per mg/kg (40–50 erythromycin doses) or parenteral divided two in forunits/day adults 1.2 million for children; units/kg/day 000 (25 IM 000–50 penicillin procaine of disease); extent on the depends performed (dosing sensitivity-testing and taken have been swabs throat after immediately dose, asingle in units) 000 (20 IM 000–100 antitoxin Diphtheria people. to uninfected organism prevention of of spread the infection; improvement of local production; of toxin termination Dosing guidelines may be found at: www.hpa.org.uk/cdph/issues/CDPHvol2/no4/guidelines.pdf. www.hpa.org.uk/cdph/issues/CDPHvol2/no4/guidelines.pdf. at: found be may guidelines Dosing or www.cdc.gov/vaccines/vpd-vac/diphtheria/dat/downloads/protocol_032504.pdf. guidelines.pdf www.hpa.org.uk/cdph/issues/CDPHvol2/no4/ at: found be may testing sensitivity for protocol The . Diphtheria antitoxin is not indicated for cutaneous disease. for cutaneous not is indicated antitoxin . Diphtheria 10 11

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Note. Clinical diphtheria does not necessarily confer natural immunity, and patients should therefore be vaccinated before discharge from a health facility.

Close contacts Surveillance for 7 days for all people with close contact, regardless of vaccination status, and throat culture. All must receive: a dose of age-appropriate diphtheria toxoid-containing vaccine, unless a dose has been received within the previous 12 months; a single dose of benzathine penicillin G IM (600 000 units for children aged < 6 years; 1.2 million units for children aged ≥ 6 years). Alternatively, a 7-day course of oral erythromycin may be used. If culture is positive, antibiotics should be given as mentioned above under Patients.

Carriers All must receive a single dose of benzathine penicillin G IM (600 000 units for children aged < 6 years; 1.2 million units for children aged ≥ 6).

Immunization During an epidemic, the population at risk should be immunized as soon as pos-

sible. In an epidemic involving adults, groups that are most affected and at highest DIPHTHERIA risk should be immunized. Immunization procedures should be repeated 1–2 months later to provide at least two doses to recipients. A third dose should be provided after 6–12 months to those without a known history of previous primary immunization. I Diphtheria and tetanus–toxoid-containing vaccine should be given. DT should be used for children < 7 years; alternatively, DTP may be used in populations with poor DTP3 coverage. For older children and adults, Td is preferred (a combination II of diphtheria toxoid of reduced content and tetanus toxoid). If Td is unavailable, DT may be used in the setting of epidemic control. In non-epidemic situations, the approach to a previously unvaccinated population is to provide a full 3-dose primary series (the first 2 doses separated by 1–2 months III and the third given 6–12 months after the second) using:

≤ 7years: DTP; ≥ 7years and adults: Td (combination reduced diphtheria and tetanus toxoid); IV routine EPI should include DTP1 (6 weeks), DTP2 (10 weeks), DTP3 (14 weeks) and if resources and circumstances permit, DTP4 (2 years).

Communicable disease epidemiological profile 44 CENTRAL AFRICAN REPUBLIC AND CHAD boxes are recommended. Safe disposal of used sharp instruments should be ensured. be should instruments sharp of used disposal Safe recommended. are boxes safety and syringes autodisable immunization, during To safety injection ensure toxoids). content tetanus and diphtheria of reduced tion toxoids). (combina tetanus given Td be and Preferably should diphtheria vaccine (age-appropriate of adults combination and adolescents >7years, for children Td and < 7years, for children given be should or DT DTP situations, endemic In Epidemiccontrol Communicable disease epidemiological profile epidemiological disease Communicable

least two doses to recipients. doses two least at one to provide later month procedures immunization Repeat risk. highest and at affected most are that groups immunize adults, involving epidemic an In children. especially possible, as soon as at risk population the Immunize to spread. likely is outbreak the which but to not affected yet areas in population of the immunization and management to case priority give measures; Implement response outbreak proved not carriers. to be until handling food to undertake not allowed must be and children with avoid must contact tacts con Adult risk. high groups at population define and contacts close Identify diphtheriae of C. toxigenicity and biotype the determine able, avail are appropriate facilities If lesions. or skin wounds any from swabs and culture for swabs and pharyngeal nasal both collect diagnosis; the Confirm status. vaccination and age of onset, record date definition, case the it fulfils whether check probable case; any Investigate guidelines. WHO following outbreak, thesuspected Confirm identified. are one or more if probable cases authorities health the Inform . - - - 45 HEPATITIS E

Country-specific disease burden Central African Republic Outbreaks took place: in April 2008, with 40 cases and no reported deaths, affecting the districts of Ombella Mpoko, Lobaye and Basse Kotto; and in July–October 2002. Further details are not available.

Chad The following outbreaks were reported: starting January 2008 and still ongoing as of end August 2008, with 934 cases and 9 deaths (CFR 0.96%) in the IDP camp Dog Doré and in Goz Amir refugee camp (health district of Goz Beida); and in June–September 2004, with 1 442 cases and 46 deaths (CFR 3.2%) in the refugee camps of Goz Amer, Goz Abal and neighbouring villages in the south-eastern area.

Description

Infectious agent E HEPATITIS Single-stranded RNA virus. Man is the natural host, although antibodies have been detected in primates and other animal species such as pigs and rodents.

Case definition I Clinical description In general, hepatitis E is a self limiting-illness followed by recovery. Prolonged viraemia or faecal shedding are unusual and chronic infection does not generally II occur, but has been described in persons who have received organ transplants. Fulminant forms of hepatitis may occasionally occur, with case-fatality ratios ranging from 0.5–4%. The fulminant form of the disease occurs more frequently during pregnancy and regularly induces a case-fatality ratio of 20% in the third 12 III trimester. It is an acute illness typically including acute jaundice, dark urine, anorexia, malaise, extreme fatigue and right upper quadrant tenderness. Biological signs include increased urine urobilonogen and > 2.5 times the upper limit of serum IV

12 http://www.who.int/topics/hepatitis/en/.

Communicable disease epidemiological profile 46 CENTRAL AFRICAN REPUBLIC AND CHAD mission by percutaneous or sexual exposures. or sexual by percutaneous mission of trans no evidence is there and investigation, under still is food contaminated from transmission HEV for potential The drinking-water. faecally-contaminated of ingestion with primarily associated is Transmission faecal–oral. Primarily Mode of transmission classification Case testing. serological by specific except hepatitis viral of acute forms other from ably reli distinguished be cannot (HEV) Evirus Hepatitis aminotransferase. alanine Communicable disease epidemiological profile epidemiological disease Communicable 13 Perennial. Seasonality common. is of drinking-water contamination wherefaecal especially Mexico, in and Africa, western and northern Asia, south-eastern and central in reported been have Epidemics area. geographical over awide occur cases sporadic and Outbreaks distribution Geographical unknown. are pathogenicity.and of national global Theburden E hepatitis ofple varying strains of multi distribution aglobal Esuggest of hepatitis cases sporadic and Epidemic General Epidemiology ingestion. after weeks four approximately and of jaundice, 14onset stools after in days detected been has HEV Unknown. period Communicability days). 15–64 (range epidemics various in days 42 to 26 from varied has period mean The Incubation period

Laboratory-confirmed case: positive for IgM anti-HEV. for positive IgM case: Laboratory-confirmed laboratory-confirmed. is that case suspected a case: Confirmed description. clinical the with compatible is that acase case: Suspected http://www.who.int/immunization_monitoring/diseases/hepatitis_surveillance/en/index.html. 13 -

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Alert threshold In the absence of a clear epidemic threshold, an epidemic should be suspected if:

multiple cases of confirmed disease are seen in a single geographical area; deaths of pregnant women are reported with fever/jaundice syndrome.

Epidemics The highest rates of infection occur in regions where low standards of sanitation promote transmission.

Risk factors for increased burden Population movement increases the likelihood of contaminated water and low hygiene. Overcrowding is highly significant, as it facilitates transmission. Poor access to health services is also a risk factor. Food shortages. Although they do not represent a direct risk factor, malnutrition increases gastrointestinal tract susceptibility to invasiveness of the organism and the severity of disease. HEPATITIS E HEPATITIS Lack of safe water and poor sanitation. Overcrowding, lack of safe water, poor hygiene and inadequate sanitation increase the risk of infection. The risk of epidemics of hepatitis E is high in camp settings. In endemic areas, the highest rates of clinically evident disease occur in young to middle-aged adults. Lower disease rates I in younger age groups may be the result of anicteric and/or subclinical infection.

Prevention and control measures Epidemic control II Prevention and detection are the key, given that there is no known therapy to alter the course of the disease and that it is spread by the faecal–oral route. The mode of transmission should be determined, the water supply investigated, populations at increased risk should be identified, and sanitary and hygiene practices improved III to eliminate contamination of food and water.

Prevention Public water supplies should be protected, purified and chlorinated. Education IV should be given to promote household-water treatment, sanitary disposal of faeces and hand-washing after defecation and before handling.

Communicable disease epidemiological profile 48 CENTRAL AFRICAN REPUBLIC AND CHAD to be effective. to be unlikely is of America United States the as such disease endemic not is an HEV world where of the parts from collected plasma from IG prepared outbreaks. HEV during disease clinical in preventing effective not been has areas endemic HEV- in collected plasma from prepared globulin Immune available. mercially development, but com yet under none are Eare Vaccines to prevent hepatitis Communicable disease epidemiological profile epidemiological disease Communicable - 49 HIV/AIDS

Country-specific disease burden Central African Republic The prevalence of HIV in adults in CAR is among the highest in all of western and central Africa, and is estimated by UNAIDS to be 6.3%, with large regional variations. The prevalence has been as high as 11% in Bamingui-Bangoran (in the north) and 14% in Haut-Mbomou (in the east), while it is about 3% or lower in Basse-Kotto (in the south) Nana-Mambéré and Ouham-Pendé (both in the west).14 The epidemic is becoming increasingly feminized with prevalence among women almost double that of men (7.8% versus 4.3%). Information on prevalence among at-risk populations such as injecting drug users or men having sex with men is not available.

HIV and AIDS estimates, Central African Republic

Adult (15–49) HIV prevalence rate 6.3% (range: 5.9–6.7%)

Adults (15+) living with HIV 140 000 (range: 130 000–150 000) HIV/AIDS

Adults (15+) and children living with HIV 160 000 (range: 150 000–170 000)

Women (15+) living with HIV 91 000 (range: 85 000–97 000) I AIDS deaths (adults and children) 11 000 (range: 9500–12 000)

Children aged 0–14 living with HIV 14 000 (range: 12 000–16 000)

Source: Report on the global AIDS epidemic. Geneva, UNAIDS, 2008.

See also: UNAIDS epidemiological fact sheet: Central African Republic, 2008 update; http://www.who.int/global II atlas/predefinedReports/EFS2008/full/EFS2008_CF.pdf; http://www.unaids.org/en/KnowledgeCentre/HIV Data/Epidemiology/epifactsheets.asp.

Chad III The most recent estimated prevalence in the adult population is 3.5% with large regional variations, generally higher in urban areas and lower in rural areas (N'Djamena, 8%; eastern Logone, 9.8%). There is no information on prevalence among injecting drug users or men having sex with men. IV

14 Ministère de l’économie, du plan et de la coopération internationale de la République centrafricaine, 2007.

Communicable disease epidemiological profile 50 CENTRAL AFRICAN REPUBLIC AND CHAD system for adults and adolescents, and for children, is outlined below. outlined is for children, and adolescents, and for adults system =en&CountryId=TCD; http://www.who.int/hiv/countries/en/index.html. =en&CountryId=TCD; http://www.theglobalfund.org/programs/grantdetails.aspx?compid=614&grantid=249&lang epifactsheets.asp; http://www.unaids.org/en/KnowledgeCentre/HIVData/Epidemiology/ Reports/EFS2008/full/EFS2008_TD.pdf; update 2008 Chad, sheet: fact Epidemiological UNAIDS also: See 2008. UNAIDS, Geneva, epidemic. AIDS global the on Report Source: Chad estimates, AIDS and HIV Communicable disease epidemiological profile epidemiological disease Communicable 15 infection HIV Primary of HIV/AIDS staging adolescents for and adults clinical WHO Revised 2006. in infection for HIV system staging the revised WHO diseases. by one indicator or more characterized illness an as defined infection, HIV of stage clinical late the is (AIDS) syndrome immunodeficiency Acquired definition Case HIV-1.than HIV-2 pathogenic less is characteristics. epidemiological similar HIV-2,and with HIV-1 haveidentified: been (HIV). types virus Two immunodeficiency Human Infectious agent Description

Children aged 0–14 living with HIV with 0–14 living aged Children children) and (adults deaths AIDS HIV (15+) with Women living HIV with living (15+) children Adults and HIV (15+) with Adults living (15–49) prevalence HIV Adult

acute retroviral syndrome. syndrome. retroviral acute infection; Asymptomatic en/index.html. at available http://www.who.int/hiv/pub/guidelines/hivstaging/ children, and adults in disease of HIV-related classification immunological and staging clinical revised and surveillance for HIV of definitions case WHO 19 000 (range: 14 00 -27 14 000) 00 (range: 19 000 000) -20 11 (range: 000 14 000 -130 000 66 000) 110 (range: 000 000) -240 130 000 (range: 000 200 000) 110 -220 (range: 000 180 000 %) 2.4–4.3 (range: 3.5% ; http://www.who.int/globalatlas/predefined ; http://www.who.int/globalatlas/predefined 15 The revised staging staging The revised 51

Clinical stage 1 Asymptomatic; persistent generalized lymphadenopathy (PGL).

Clinical stage 2 Moderate unexplained weight loss (< 10% of presumed or measured body weight), recurrent respiratory tract infections (sinusitis, bronchitis, otitis media, pharyngitis); herpes zoster; angular cheilitis; recurrent oral ulcerations; papular pruritus eruptions; seborrheic dermatitis; fungal nail infections of fingers.

Clinical stage 3 Unexplained severe weight loss (> 10% of presumed or measured body weight); HIV/AIDS unexplained chronic diarrhoea for longer than one month; unexplained persistent fever (> 37.6 °C intermittent or constant, for longer than one month); I persistent oral candidiasis; oral hairy leukoplakia; pulmonary tuberculosis (current); severe bacterial infections (such as pneumonia, empyema, pyomyositis, bone II or joint infection, meningitis or bacteraemia); acute necrotizing ulcerative stomatitis, gingivitis or periodontitis; unexplained anaemia (< 8 g/dl), neutropaenia (< 0.5 × 109 per litre) or chronic thrombocytopaenia (< 50 × 109 per litre). III

Clinical stage 4 HIV wasting syndrome; IV pneumocystis pneumonia; recurrent severe bacterial pneumonia;

Communicable disease epidemiological profile 52 CENTRAL AFRICAN REPUBLIC AND CHAD Clinical stage 2 stage Clinical Communicable disease epidemiological profile epidemiological disease Communicable 1 stage Clinical of HIV/AIDS staging for children clinical WHO Revised

lineal gingival erythema; gingival lineal cheilitis; angular infection; nail fungal eruptions; pruritic papular hepatosplenomegaly; persistent Unexplained (PGL). lymphadenopathy generalized persistent Asymptomatic; cardiomyopathy. HIV-associated or symptomatic nephropathy HIV-associated symptomatic leishmaniasis; disseminated atypical carcinoma; cervical invasive tumours; HIV-associated solid or other non-Hodgkin) (cerebral orlymphoma B-cell Salmonella non-typhoidal recurrent mycosis (coccidiomycosis or histoplasmosis); disseminated isosporiasis; chronic diarrhoea); (with cryptosporidiosis chronic leukoencephalopathy; multifocal progressive infection; mycobacterial non-tuberculous disseminated meningitis; including cryptococcosis extrapulmonary encephalopathy; HIV toxoplasmosis; system nervous central organs); of other or infection (retinitis infection cytomegalovirus sarcoma; Kaposi tuberculosis; extrapulmonary bronchior lungs); of trachea, (or candidiasis candidiasis oesophageal site); at any or visceral one month’s duration of more than or anorectal (orolabial, genital infection simplex herpes chronic bacteraemia; 53

extensive wart virus infection; extensive molluscum contagiosum; recurrent oral ulcerations; unexplained persistent parotid enlargement; herpes zoster; recurrent or chronic upper respiratory tract infections (otitis media, otorrhoea, sinusitis or tonsillitis).

Clinical stage 3 Unexplained moderate malnutrition or wasting not adequately responding to standard therapy; unexplained persistent diarrhoea (14 days or more); unexplained persistent fever (above 37.5 °C intermittent or constant for longer than one month); persistent oral candidiasis (after first 6–8 weeks of life); oral hairy leukoplakia; acute necrotizing ulcerative gingivitis or periodontitis; lymph node tuberculosis; HIV/AIDS pulmonary tuberculosis; severe recurrent bacterial pneumonia; I symptomatic lymphoid interstitial pneumonitis; chronic HIV-associated lung disease including brochiectasis; unexplained anaemia (< 8 g/dl), neutropaenia (< 0.5 × 109 per litre) and or chronic thrombocytopaenia (< 50 × 109 per litre). II Clinical stage 4 Unexplained severe wasting, stunting or severe malnutrition not responding to standard therapy; III pneumocystis pneumonia; recurrent severe bacterial infections (such as empyema, pyomyositis, bone or joint infection or meningitis but excluding pneumonia); chronic herpes simplex infection (orolabial or cutaneous of more than one IV month’s duration or visceral at any site); oesophageal candidiasis (or candidiasis of trachea, bronchi or lungs);

Communicable disease epidemiological profile 54 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable including: settings disaster and emergency in advantages several affords tests rapidHIV of use The tests. ELISA of WHO-recommended those to comparable specificity and of have sensitivity levels and centres collaborating WHO at evaluated WHO have been by are recommended that rapidThe tests first. of the independent genically and/or anti methodologically is (IFA) that test ELISA orantibody asecond test fluorescent indirect the the blot, as such Western specificity of higher test another with confirmed itbe must or EIA, by ELISA positive is test antibody HIV the When about 3 months. lasts period window This transmitted. be can infection HIV and actively replicates virus the time However, this tests. during HIV current by low too detected to be are levels but the to produce antibodies, starts body the which during period window the called period is a there infection, EIA). After immuneassay, or enzyme (ELISA, assay immunosorbent enzyme-linked using samples serum in antibody HIV done by detecting commonly most is testing HIV of HIV evidence Laboratory

tests are performed. are tests few whererelatively sites and for remote areas especially important, also is life supply. shelf- Long electricity aguaranteed without sites and areas rural and for moreremote be suitable will refrigeration do not require that tests Rapid cardiomyopathy. or HIV-associated nephropathy HIV-associated symptomatic leukoencephalopathy; multifocal progressive lymphoma; non-Hodgkin or B-cell cerebral isosporiasis; chronic diarrhoea); (with cryptosporidiosis chronic infection; mycobacterial non-tuberculous disseminated mycosis (coccidiomycosis endemic or histoplasmosis); disseminated encephalopathy; HIV meningitis); (including cryptococcosis extrapulmonary life); toxoplasmosis(after 1 of month system nervous central 1month; older at than age onset organ,with another affecting infection or cytomegalovirus retinitis infection: cytomegalovirus sarcoma; Kaposi tuberculosis; extrapulmonary - 55

Many rapid tests require no laboratory equipment and can be performed in settings where electrical and water supplies need not be guaranteed. Some rapid tests can detect HIV antibodies in whole blood (finger-prick samples) as well as serum/plasma, and testing may therefore be performed by non-laboratory personnel with adequate training and supervision.

Mode of transmission Sexual intercourse (vaginal or anal) with an infected partner, especially in presence of a concurrent ulcerative or non-ulcerative sexually transmitted infection (STI). The primary route of HIV infection is heterosexual. Infected mother to her child during pregnancy, labour and delivery or through breastfeeding. Transfusion of infected blood or blood products. Contaminated needles, syringes, other injecting equipment and injecting solutions (contamination often occurs when drug solutions are mixed or when multiple users draw up solutions from a single container), through accidental injury of patients or service providers in occupational health, or those who are injecting drug users.

Incubation HIV/AIDS Variable. On average, the time from HIV infection to clinical AIDS is 8–10 years, although AIDS may be manifested in less than 2 years or be delayed in onset beyond 10 years. Incubation times are shortened in resource-poor settings and in older patients. I Communicability period Any person who is infected with HIV, even when asymptomatic, may transmit the infection to another person through the routes of transmission described above. Infectiousness is observed to be high during the initial period after infec- II tion. Studies suggest infectiousness increases with the viral load (number of viral elements in the blood), which is high during the initial stage of contamination and also later when AIDS develops, with increasing immune deficiency, clinical symptoms and presence of opportunistic infections. III

Epidemiology General IV Sub-Saharan Africa remains the worst-affected region in the world. With just over 10% of the world’s population, it is home to more than 60% of all people living

Communicable disease epidemiological profile 56 CENTRAL AFRICAN REPUBLIC AND CHAD newly infected, while 2.4 million adults and children died of AIDS. died children and adults million 2.4 while infected, newly became region the in people million 3.2 estimated HIV. an 2005, with In living were Africa sub-Saharan in people million 25.8 HIV. end of 2006, with At the Communicable disease epidemiological profile epidemiological disease Communicable 16 investigated. be must case suspected One thresholdAlert Not applicable. Seasonality Global. distribution Geographical children in other situations. other in children than more exposed thus are and opportunities, education and schooling average below- may have few occupations, settings camp in Children health. Adolescent pathogens. bloodborne other and for HIV tested is blood that to ensure and transfusions blood to avoid unnecessary It important is safety. blood ensure to difficult have particularly it brokenis down, services fusion trans regular when situations, emergency In virus. the of transmitting 100% risk almost an carries blood HIV-infected with Transfusion transfusions. blood Unsafe infected. is sharing people one of the if transmission of HIV risk high avery carries that apractice needles, sharing be will injectors drug that use. drug Injecting practised. is sex unprotected if infection of HIV at risk are clients and workers sex Both communities. host and refugee the both involves inevitably and camps refugee or around money, in common as is such etc., shelter,needs, security, work. Sex sex. violent during torn are tissues body if more easily transmitted be can virus the because and sex, unsafe from themselves protect cannot violated those because of infection risk ahigher carries violence Sexual or rape. abuse coercion, of sexual risk at particular children women and with powerless, socially and physically often are persons Displaced violence. Sexual women (13.2 are million). Africa sub-Saharan in HIV with living adults of all

UNAIDS estimates available at: http://www.unaids.org/en/Regions_Countries/default.asp). at: available estimates UNAIDS The need to exchange sexual favours for survival and ensuring basic basic andensuring favours forsurvival sexual exchange to The need In the typical conditions of an emergency, it is highly likely likely emergency, of an highly it is conditions typical the In 16 Around 59% 59% Around - 57 Risk factors for increased burden Population movement In emergency situations, population movement often causes a breakdown in family and social ties and erodes traditional values and coping strategies. It may result in lack of privacy and high-risk sexual behaviour, but may also increase sexual violence. Lack of information and education, and shortages of basic commodities for preventing HIV such as condoms in such settings, may also increase the risk of HIV transmission.

Overcrowding Groups with differing levels of HIV awareness and of HIV prevalence are often placed together in temporary and sometimes overcrowded locations, or are in contact with surrounding populations such as in refugee camps, where there is greater potential for sexual contact. Overcrowding may also influence patterns of injecting drug use and result in an increased risk of contaminated injection equipment being shared (this has been noted in refugee camps).

Poor access to health services

People already infected with HIV are at greater risk of physical deterioration HIV/AIDS during an emergency because:

the health-care system may break down (attacks on health centres, inability I to provide supplies, flight of health-care staff); caregivers may be killed or injured during an emergency, leaving behind children already made vulnerable by infection with HIV/AIDS or loss of parents to AIDS; II populations have limited physical access to health facilities owing to roads being blocked; the financial resources required to maintain basic services are more limited than usual; III they are more likely to suffer from disease and death as a consequence of limited access to food, clean water and good hygiene as a result of weakened immune systems; there may be stigma and discrimination towards AIDS patients; IV basic commodities and HIV services, condoms, education and communication, testing and counselling services are lacking;

Communicable disease epidemiological profile 58 CENTRAL AFRICAN REPUBLIC AND CHAD to sterile injection equipment will be less likely. likely. less be equipment will injection to sterile access and do not exist, usually treatment for drug-dependence services situations, emergency In situation. emergency an in lacking to be likely are condoms, ticularly prevention, par for HIV materials HIV. Important of acquiring risk the increase greatly partner, either in untreated left if STIs, services, medical adequate Without Food shortages Communicable disease epidemiological profile epidemiological disease Communicable transmission Reduce sexual Prevention Prevention and control measures

shortages more rapidly and severely. and more rapidly shortages of food consequences the suffer will and requirements nutritional have greater HIV/AIDS may occur. patients essentials other for moneysex and to buy food exchanging that so situations, emergency in paramount is forThe need food limited. is shelf-life their and may vary, regimen and needs drugs ART needed, are systems procurement separate as difficult is ARV drugs accessing those who need them, using culturally sensitive instructions and distribution. and instructions sensitive culturally using them, need who those to available freely condoms are quality good that Condom promotion to ensure principles. hygiene of basic and necessary; if attention medical and of charge condoms free of how whereto acquire and of transmission; amode constitute not, does and does, of what informed: well is everyone that to ensure for people, young especially education, life-skills Awareness and etc.). hyperlipidaemia, resistance, insulin as such side-effects (metabolic ARTs of side-effects the as etc.) well sore mouth, as nausea, (e.g. diarrhoea, HIV of the side-effects alleviating in role key a diet plays the of The quality loss. weight experiencing children in requirements by 50–100% above normal increased to be need intakes Energy weight. body adult to maintain 20–30% by approximately ments increase require energy AIDS, during HIV, subsequently symptomatic and During children. asymptomatic in growth and adults, HIV-infected asymptomatic in activity physical and weight body by 10% to maintain to increase likely are requirements Energy not is infected. who of aperson needs to the compared energy extra with diet of HIV/AIDS abalanced need in are with People living - - 59

STI management, including for sex workers, using the syndromic STI management approach, with partner notification and promotion of safer sex.

Reduce mother-to-child transmission of HIV Most children living with HIV acquire the infection through mother-to-child transmission (MTCT), which may occur during pregnancy, labour, delivery or during breastfeeding. The risk of MTCT may be reduced to under 2% by interventions that include: antiretroviral (ARV) prophylaxis given to women during pregnancy and labour and to the infant in the first weeks of life; obstetric interventions including elective caesarean delivery (prior to the onset of labour and rupture of membranes), and complete avoidance of breastfeeding; where elective caesarean delivery is not possible, avoidance of unnecessary obstetrically invasive procedures, such as artificial rupture of membranes or episiotomy. In the absence of any intervention, the risk of MTCT is 15–30% in non-

breastfeeding populations. Breastfeeding by an infected mother increases the HIV/AIDS risk by 5–20% to a total of 20–45%. In many resource-constrained and emergency settings, elective caesarean delivery is seldom feasible and it is often neither acceptable nor safe for mothers I to refrain from breastfeeding. In these settings, the efforts to prevent HIV infection in infants initially focused on reducing MTCT around the time of labour and delivery, which accounts for between one third and two thirds of overall transmission. II Many countries with a heavy burden of HIV have recently adopted more effective ARV regimens, beginning in the third trimester of pregnancy, which may reduce the risk of transmission during pregnancy and childbirth to 2–4%. Even when these regimens are used, however, infants remain at substantial III risk of acquiring infection during breastfeeding. Where feasible, acceptable, affordable, sustainable and safe methods are available, infant-feeding practices should be modified. Otherwise, exclusive breastfeeding for the first months of life is recommended. IV The primary prevention of HIV among women, especially young women, should be emphasized.

Communicable disease epidemiological profile 60 CENTRAL AFRICAN REPUBLIC AND CHAD Prevention among injecting drug users drug Prevention injecting among safety Blood Communicable disease epidemiological profile epidemiological disease Communicable com in deployed workers health Often, care. and testing counselling, to voluntary have access workers should HIV. with Health-care infected to be known are they or not –whether samples laboratory and patients all with precautions to universal adhere strictly workers should health transmission, order nosocomial to reduce In workers health-care Protecting infection. of HIV risk the for reducing essential but also is rights of human principle important an not is only abuse lence and vio from children, and women especially vulnerable, the most of The protection protection Physical precautions Universal

Recruitment of safe blood-donor pool. of safe Recruitment transfusion. blood Avoid non-essential blood. transfused of all testing HIV HIV.with infected women are who in particularly promoted, methods planning family and avoided, women be should HIV-infected among pregnancies Unintended ments. Proper cleaning and disinfection of medical instruments between patients. between instruments of medical disinfection and cleaning Proper ments. instru sharp other and needles material, of waste disposal and handling Safe fluids. body infected potentially or other blood with of contact risk is there when clothing and gloves protective Using or wounds. fluids body with contact after water, and soap especially with thoroughly hands Washing users. drug HIV/AIDS for and injecting to STI treatment Access methadone) wherepossible. (e.g. treatment substitution including services, treatment Drug-dependence possible). when outreach peer ing (includ users drug for injecting counselling and education risk-reduction HIV equipment). of used disposal equipment (and injection other and syringes needles, to sterile access Ready - - - - 61 plex emergencies experience significant occupational stress and those tested, as part of the management of occupational exposures, will require additional support.

Voluntary counselling and testing programmes The establishment of voluntary counselling and testing services to help individuals make informed decisions about HIV testing should be considered when relative stability is restored. At times, people are coerced into testing or are required to make decisions about testing when they are suffering acute or post-traumatic stress disorders. As displaced persons are often tested before resettlement in other countries, it is critical that they receive counselling on the legal and social implications of the test. Often, migration or temporary residency status is contingent on the appli- cant having HIV-antibody seronegative status. Post-test counselling is essential for people with both seronegative and seropositive results. Displaced persons and conflict survivors who are already traumatized will require additional psychosocial support if they test seropositive. Typically, the support networks of displaced persons are disrupted, and suicide risk assessment therefore forms an important part of post-test counselling in a refugee or conflict context. HIV/AIDS Testing of orphaned minors should be carried out with the consent of their official guardians, only where there is an immediate health concern or benefit to the child. There should be no mandatory screening before admittance to substitute care. I Immunization Asymptomatic HIV-infected children should be immunized with the Expanded Programme on Immunization (EPI) vaccines. II Symptomatic HIV-infected children should not receive either BCG or yellow fever vaccine.

Case management III The three main interventions are:

1. post-exposure prophylaxis (PEP) and prevention of mother-to-child transmission (PMTCT); IV 2. antiretroviral therapy (ART); 3. nutritional care.

Communicable disease epidemiological profile 62 CENTRAL AFRICAN REPUBLIC AND CHAD initiating ART. initiating for recommendations table provides The following not is available. testing CD4 where situations in to ART switch and to start when and prophylaxis trimoxazole co- on to start when decisions to guide used is and programme treatment and care into a visit) (first entry on assessment baseline of the Itpart form should ing. test HIV-antibody by confirmed been has infection HIV after situations crisis and emergency in intended use for is staging Clinical systems. classification paediatric and adult the between consistency order greater to provide in vised been re recently has disease clinical HIV-associated of WHOclassification The started? ART be should 1. When disease. symptomatic with patients in stage clinical of the reversal effective about brings and status improvement clinical in in results ART intensified. be should services health reproductive and prevention of STIs counselling, post-test and pre- andtesting, counselling coverage of voluntary nationwide increase to Efforts exist. they implemented if be should ART of use on guidelines national Country-specific countries. for developed reported those to similar rates have efficacy settings resource-poor in programmes ART (ART) therapy (2) Antiretroviral HIV. to exposure of risk on adefined based PEP are for and PMTCT for eligibility criteria of ARV provision minimum for prevention, the allow conditions When (PEP). prophylaxis post-exposure and (PMTCT) transmission prevention of mother-to-child the include tions interven Prophylactic individuals. exposed in ARVs infection prevent HIV can (ARVs)(1) of antiretrovirals Provision for prevention Communicable disease epidemiological profile epidemiological disease Communicable 17

a discussion paper a discussion (HIV-PEP) infection HIV for prophylaxis post-exposure non-occupational and occupational on guidelines and policy of development the for meeting technical WHO ILO/ joint the of report Summary (http://www.who.int/hiv/pub/guidelines/PEP/en/index.html); infection (HIV) virus immunodeficiency human (PEP) prevent to prophylaxis post-exposure non-occupational and occupational of use the for guidelines WHO/ILO joint infection: HIV prevent to prophylaxis Post-exposure (http://www.who.int/hiv/topics/mtct/en/index.html); HIV of transmission Mother-to-child to: refer Please 17 Post-exposure prophylaxis following non-occupational exposures. non-occupational following prophylaxis ; Post-exposure Occupational post-exposure prophylaxis for HIV: HIV: for prophylaxis post-exposure ; Occupational

- - - 63

Recommendations for initiating ART in adults and adolescents according to clinical stages and the availability of immunological markers

WHO clinical Classification CD4 testing not available CD4 testing available staging

1 Asymptomatic Do not treat Start treatment if CD4 count < 200 cells/mm3

2 Mild Do not treat Start treatment if CD4 count < 200 cells/mm3

3 Advanced Treat Consider treatment if CD4 < 350 cells/mm3 and initiate ART before CD4 count drops below 200 cells/mm3

4 Severe Treat Treat irrespective of CD4 cell count

After a patient has been tested HIV-positive and shows symptoms of AIDS (see Case definition/clinical staging above), the process of initiating ART involves assessing patient readiness to commence therapy and understanding its implications (lifelong therapy, adherence, toxicities). Support from family and peer support HIV/AIDS from individuals (“treatment buddy”) groups is critical when ART is initiated, as adherence to treatment is difficult but essential to the treatment efficacy, but also to prevent drug resistance. I High-quality care and support to all people living with HIV/AIDS (PLWHA) includes counselling, psychosocial and nutritional support, treatment for opportunistic infections (e.g. TB) and palliative care. Importantly, PLWHA should be supported to live normal and productive lives that are free of stigmatization and II discrimination.

Current WHO recommendations require that the first-line regimen for adults and adolescents contain two nucleoside reverse transcriptase inhibitors (NRTIs) III plus one non-nucleoside reverse transcriptase inhibitor (NNRTI) (see the figure below). This first-line regimen, based on a combination of two NRTIs plus one NNRTI, is efficacious, generally less expensive than other regimens, has generic formulations, is often available as fixed-dose combinations (FDCs) and does not IV require a cold chain. In addition, it preserves a potent new class of drugs (protease inhibitors) for second-line treatments.

Communicable disease epidemiological profile 64 CENTRAL AFRICAN REPUBLIC AND CHAD drug from the first-line regimen. The toxicities of first-line first-line of recommended and The ARVs toxicities regimen. first-line the from drug another be and prescribed intolerance or side effects toxic may experience Patients another? by be replaced drug regimen afirst-line should When 2. d c b a nevirapine NVP: EFV: efavirenz; emtricitabine; FTC: lamivudine; 3TC: abacavir; ABC: tenofovir; TDF: D4T: stavudine; zidovudine, AZT: adolescents and adults for ARV drugs First-line Communicable disease epidemiological profile epidemiological disease Communicable be observed: that must precautions various are There

inhibitor (PI), provided that caution and close monitoring are practised. are monitoring close and caution (PI), that inhibitor provided protease boosted with TDF +didanosine to consider possible it is situation which in treatment, second-line for be reserved should didanosine of use The failure. virological of early rates high with associated also are NNRTI any + TheTDFofcombinations didanosine + failure. logical viro of early incidences high with associated are K65R and for mutation the select TDFdidanosine and + 3TC + TDFABC of + 3TC + combinations The together).used (overlapping not but be should (interchangeable, 3TC +FTC and toxicities) AZT are(provenantagonism), d4Tdidanosine d4T + therapy. + These drug three- within not used be should combinations backbone NRTI dual Certain prophylaxis. post-exposure and of PMTCT setting the in only used may be they infection; HIV chronic to treat used be not should therapy or dual Monotherapy coinfection, TB coinfection, severe reactions to NVP or EFV, and HIV-2 infection). HIV-2 EFV, infection). or and NVP to reactions severe coinfection, TB coinfection, hepatitis viral cells/mm3, 350 and 250 between counts CD4 have who women (e.g. complications additional provide options NNRTI where situations in regimens first-line for alternative an as considered be may circle) dotted the shown within options the from only selected Triple drugs approach NRTI (i.e.NRTI three regimens. first-line standard in FTC or 3TC with combined be to NRTI Preferred NNRTI. the as EFV or NVP either with combined NRTIs two upon approach drugs: is aofbased combination three NRTIs/NNRTI two Preferential developed. been have that treatment ARV for guidelines national country-specific any of consideration with used be should recommendations These TDF AZT Preferential two NRTIs/NNRTI approach NRTIs/NNRTI two Preferential c c or ABC or or d4T or Triple NRTI approach NRTI Triple 3TC FTC ou d b a NVP EFV - 65 drug substitutions are provided in the table below. Another example would be the need to substitute Efavirenz for pregnant women.

Toxicities of first-line ARVs and recommended drug substitutions

ARV drug Common associated toxicity Suggested substitute

ABC Hypersensitivity reaction AZT or TDF or d4T

AZT Severe anaemiaa or neutropeniab TDF or d4T or ABC Severe gastrointestinal intolerancec

Lactic acidosis TDF or ABCd

d4T Lactic acidosis TDF or ABCd Lipoatrophy/metabolic syndromee

Peripheral neuropathy AZT or TDF or ABC

TDF Renal toxicity AZT or ABC or d4T (renal tubular dysfunction)

EFV Persistent and severe central nervous NVP or TDF or ABC (or any PI)h system toxicityf

Potential teratogenicity (first trimester of NVP or ABC (or any PI)h pregnancy or women not using adequate HIV/AIDS contraception)

NVP Hepatitis EFV or TDF or ABC (or any PI)h

Hypersensitivity reaction TDF or ABC (or any PI)h I Severe or life-threatening rash (Stevens-Johnson syndrome)g a Exclude malaria in areas of stable malaria; severe anaemia (grade 4) is defined as Hb < 6.5 g/dl. b Defined as neutrophil cell count < 500/mm3 (grade 4). II c Defined as severe, refractory gastrointestinal intolerance that prevents ingestion of ARV drug regimen (e.g. persistent nausea and vomiting). d Reinitiation of ART should not include d4T or AZT in this situation. TDF or ABC is preferred. e Substitution of d4T may not reverse lipoatrophy. f E.g. persistent hallucinations or psychosis. III g Severe rash is defined as extensive rash with desquamation, angioedema, or a reaction resembling serum sickness; or a rash with constitutional findings such as fever, oral lesions, blistering, facial oedema or conjunctivitis; Stevens-Johnson syndrome can be life-threatening. For life-threatening rash, substitution with EFV is not recommended, although this approach has been reported in a small number of patients in Thailand without recurrence of rash. IV h PI class should be preferentially reserved for second-line therapy as no potent regimens have been identified for recommendation following initial PI failure.

Communicable disease epidemiological profile 66 CENTRAL AFRICAN REPUBLIC AND CHAD adults and adolescents and adults in ARV regimens second-line to switching for recommendations Detailed may not available. be regimens second-line settings, emergency In difficult. is process procurement the and refrigeration need most expensive, are more drugs these as challenge is a ARVdrugs second-line of The availability above. described regimens first-line of the failure experience who adults and cents adoles in considered to be strategies second-line the below, table the indicating given are ARV regimens to second-line for switching recommendations Detailed consistently. medicines first-line ART taking been has patient the while develop of AIDS symptoms and failure treatment is there when made be should regimen second-line to a afirst- from A change regimen? second-line by a be replaced regimen afirst-line should When 3. Communicable disease epidemiological profile epidemiological disease Communicable correct the to obtain providers care and patient to the support include should care HIV. with Nutritional of living people care the role in akey plays care Nutritional HIV/AIDS with (3) for people living care Nutritional d c b a Alternative strategy Standard strategy First-line regimen IDV/r, LPV/r and SQV/r) and the choice should be based on individual programme priorities. In the the In PI. RTV-boosted priorities. programme an than potent less individual considered but it is PI component on the as employed be may NFV based chain, of a cold absence be should choice the and SQV/r) and LPV/r IDV/r, PIs (ATV/r,RTV-boosted FPV/r,available currently among differences detect data to insufficient are There mutation. K65R the of emergence the delay or prevent may TDF.or AZT AZT to sensitivity viral improve to M184Vmutation the on pressure maintain and activity antiviral residual 3TC may be considered to be maintained in second-line regimens to potentially reduce fitness,viral confer pharmaco profiles. share resistance and and related properties logical structurally are they because interchangeable considered are FTC and 3TC chain. acold without settings in aPI alternative as used be may and refrigeration need not does NFV ABC +3TC TDF +3TC AZT ord4T+3TCAZT ord4T+3TCAZT b b +NVPorEFV + NVPorEFV b b + TDF orABC +NVPorEFV RTI component EFV orNVP±ddI TDF +3TC (±AZT) TDF +ABCor ddI +ABCor ddI +3TC (±AZT) ddI +ABCor TDF +3TC (±AZT) ddI +3TC (±AZT) c c Second-line regimen Second-line c c or PI component PI/r d a -

67 quantities of food, and individual nutrition counselling should be given to patients and their caregivers in order to improve the quality of feeds. Nutritional care and support is important to alleviate the side-effects of HIV/AIDS as well as the side- effects of ARTs.

4. When and how should ART be stopped? If a patient has exhausted all available antiretroviral and opportunistic treatment options and is clearly in a terminal condition because of advanced HIV infection or has distressing or intolerable side-effects of therapy, it is reasonable to stop giving ARVs and institute an active palliative and end-of-life care plan. In case of an emergency or disaster where drug shortages are likely, patients should be given strategies to help manage a treatment disruption. It is important through education and adherence counselling to prevent alterations in the drug regime such as change in dosages, irregular treatment, or drug sharing. If ARV supplies are running out, the treatment should be stopped completely. Patients should be informed not to conserve medications, change dosing regimens, and to avoid acquiring ARVs from unofficial sources, as the quality of the drugs cannot be guaranteed. HIV/AIDS In case of treatment disruption of a treatment regimen including nevirapine or efavirenz experts recommend to supply patients with an additional supply of seven days of the two other drugs of the treatment, nucleoside reverse transcriptase inhibitor (NRTI) drugs, e.g. lamivudine (3TC) and stavudine (D4T) or 3TC and I zidovudine (ZDV). This “wash-out” treatment period with two NRTI drugs is intended to cover the time it takes for the non-nucleoside reverse transcriptase inhibitors (NNRTIs) to be eliminated from the system, as NNRTIs last longer in the bloodstream. For other regimens, should the treatment be discontinued, it II should be stopped as soon as any drug is missing and patients should be trained not to take the remaining doses of incomplete treatment.

References III 1. WHO HIV/AIDS guidelines (http://www.who.int/hiv/pub/en/index.html http://www.who.int/ hiv/pub/guidelines/en/). 2. Antiretroviral therapy for HIV infection in adults and adolescents in resource-limited settings: towards universal access recommendations for a public health approach. Geneva, World Health IV Organization, 2006 (http://www.who.int/hiv/pub/guidelines/WHO%20Adult%20ART%20 Guidelines.pdf).

Communicable disease epidemiological profile 68 CENTRAL AFRICAN REPUBLIC AND CHAD 9. 8. 7. 6. 5. 4. 3. Communicable disease epidemiological profile epidemiological disease Communicable

(http://www.who.int/hiv/pub/sti/en/stdcontrol_en.pdf). 1998 UNAIDS, Geneva, update. technical control: STD to approach health public The HIV and AIDS and HIV with living people for support and care nutritional on Amanual HIV/AIDS. with well Living (http://www.who.int/hiv/pub/mtct/en/HIVandInfantFeeding.pdf). 2003 action priority for aframework feeding: infant and HIV (http://who.arvkit.net/tc/en/index.jsp). counselling and testing HIV for toolkit On-line programmingguide.pdf). (http://www.who.int/hiv/pub/prev_care/policy 2005 Organization, World Health Geneva, users drug injecting among care and HIV/AIDS prevention for guide programming and Policy (http://www.who.int/3by5/publications/documents/imai/en/index.html). 2006 Organization, modules (IMAI) Illness Adult and Adolescent of Management Integrated WHOPMTCT.pdf). health approach public a for recommendations access universal towards settings: resource-limited in infants in infection HIV preventing and women pregnant treating for drugs Antiretroviral . Geneva, World Health Organization, 2006 .(http://www.who.int/hiv/pub/guidelines/World Geneva, 2006 Organization, Health . FAO/WHO, 2002 (http://www.fao.org/docrep/005/y4168e/y4168e00.htm). . FAO/WHO, 2002 . Geneva, World Health Organization, 2004 2004 Organization, World Health . Geneva, . Geneva, World Health Organization, Organization, World Health . Geneva, . Geneva, World Health World Health . Geneva,

. 69 INFLUENZA (SEASONAL)

Country-specific disease burden No country data are available for the Central African Republic and Chad.

Description Infectious agent Influenza viruses A, B and C: influenza virus A that has multiple subtypes, of which two (H1N1 and H3N2) are currently circulating widely among humans; other influenza A subtypes of animal origin (16 HA and 9 NA subtypes), of which several (H5, H7 and H9) have caused sporadic human infections in some countries.

Case definition Clinical case definition A person with rapid onset of fever of > 38 °C and cough or sore throat in the absence of other diagnoses. Diagnosis can be made on the basis of epidemiological INFLUENZA (SEASONAL) characteristics: cases with similar clinical presentation usually cluster or form an epidemic typically with short intervals between case onset (1–4 days). The positive predictive value of this case definition is highest when influenza is circulating in the community (and is higher in adults or adolescents than in young children). I

Case classification Suspected: a case that meets the clinical case definition. Confirmed: a case that meets the clinical case definition and is laboratory- II confirmed.

Laboratory criteria for diagnosis Laboratory confirmation of influenza infection may be done by isolation of viruses III from throat, nasal or nasopharyngeal secretions or tracheal aspirate of washings using cell culture or in embryonated eggs; direct identification of viral antigens in nasopharyngeal cells and fluids (FA test or ELISA); rapid diagnostic test; or viral RNA amplification. Demonstration of a 4-fold or greater rise in specific antibody IV titre between acute and convalescent sera may also be used to confirm acute infection. Ideally, respiratory specimens should be collected as early in the illness as

Communicable disease epidemiological profile 70 CENTRAL AFRICAN REPUBLIC AND CHAD seasonal epidemic period when reliable surveillance data are available. are data surveillance reliable when period epidemic seasonal a recognized during symptoms typical by clinically diagnosed maybe Influenza apart). weeks two at least collected samples (paired a recentinfection suggests serum aconvalescent and acute an between ≥4-fold rise titre antibodies studies). An outbreak, of seasonal of (detection start purposes epidemiological for It used may be diagnosis. for retrospective rather used is and management clinical immediate in useful rarely is specimens serum in detection Antibody 2–10 year. It takes days. coming the for vaccine and to formulate andchemoprophylaxis treatment influenza garding re decisions guide to needed is This strains. and subtypes influenza circulating regarding information to provide It critical is viruses. the to test reagents ardized (3) (3) afew hours. within available be can Results culture. than moresensitive in general are and RNA virus influenza viable (2) 15–30 minutes. within available are Results tests. these with a major concern are results false-negative low90–95%). of sensitivity, the Because 70–75%) high is (median specificity their while lowerand of culture, that cell than commercially available. In general, the sensitivity of rapid tests is variable (median are assay) or neuraminidase immunoassays (enzyme rapid testing point-of-care (1) specimens respiratory in detection Antigen children. in for alonger period occur may shedding virus although adults, in days 5 after not is detected virus the cases most in and of day symptoms, third by the to wane starts shedding Virus possible. Communicable disease epidemiological profile epidemiological disease Communicable 1–7 2days) symptoms. to develop for between (usually aperson days takes Incubation unknown. currently are transmission influenza of modes different the of importance clinical and contributions The relative over possible. 1mis mission trans airborne that or eye). nose into indicates evidence Some self-inoculation and contamination hand (e.g. with contact fomites, indirect, perhaps and direct, through 1mand than closer at distances droplets (> 5 μm) respiratory particle large to exposure through occurs viruses influenza of human transmission The Mode of transmission (for A and B seasonal influenza). Near-patient tests, or tests, Near-patient influenza). (for Bseasonal tests Aand diagnostic Rapid Virus culture Virus (PCR). reaction chain Polymerase . This is considered as the “gold standard”. WHO provides stand WHO provides the “goldas standard”. considered is . This RT-PCR assays detect both viable and non- and viable RT-PCR both detect assays - - - 71

Communicability period The patient may have detectable virus and possibly be infectious from 1−2 days before onset of symptoms. Infectiousness may last for up to 7 days after onset of illness in adults (perhaps longer if infection is caused by a novel virus subtype), and for up to 21 days after onset in children aged < 12 years.

Epidemiology Geographical distribution The influenza virus circulates globally.

Seasonality In some tropical countries, viral circulation occurs year-round with peaks during rainy seasons. In temperate countries, influenza epidemics peak during winter months. High attack rates (47.4%) with a case-fatality rate of 1.5% were reported during seasonal influenza epidemics in the Democratic Republic of the Congo and Madagascar in 2002. In Madagascar, despite rapid intervention within three months, more than 27 000 cases and 800 deaths were reported.18 INFLUENZA (SEASONAL) Alert threshold An increase in the number of cases above what is expected for a certain period of the year or any increase in cases of fever of unknown origin should be investigated, I after eliminating other causes. Accumulated surveillance data are required to determine the threshold. Currently, no such data are available for CAR and Chad.

Risk factors for increased burden II Population movement is a risk factor, because of the influx of non-immune populations into areas where the virus is circulating, or of infected individuals into areas with immunologically naive population. Overcrowding with poor ventilation facilitates transmission and rapid spread. III Poor access to health services. Prompt identification, isolation and treatment of the cases (especially treatment of secondary bacterial pneumonia by antimicrobials) are the most important control measures (see section on Case management). IV

18 See: http://www.who.int/docstore/wer/pdf/2003/wer7813.pdf.

Communicable disease epidemiological profile 72 CENTRAL AFRICAN REPUBLIC AND CHAD populations with limited access to adequate health care. health to adequate access limited with populations crowded densely poorly nourished, in consequences severe health be could There situation. geographical its and country on the depending it may vary and Africa, in conclusions. assessment Risk (such tuberculosis). as of latent infections vation of reacti possibly and of HIV activity for increased risk apotential is there that so function, immune cellular depress transiently may itself infection Influenza higher. is administration drug after, enduring potentially and during, emergence resistance of antiviral risk of increased likelihood the and more frequent, are tions rarely, to, months).(weeks be protracted Complica could replication viral affected, is individual on how the severely Depending individuals. Immunocompromised prolonged and illness. for complications factor arisk is Smoking spaces). living of ventilation insufficient with indoors, of individuals proximity increased (home confinement, transmission increased in may result that conditions to crowded lead living may also temperatures Low environment. the in survival to longer virus contribute conditions dry and Lowertemperatures factors. Other spread. facilitate and practices may hand-washing reduce sanitation poor and water safe of Lack of illness. may prolongduration complications the and development disease, of the and for infection factors risk important to be likely are practices breastfeeding poor and Adeficiency vitamin malnutrition, weight, birth Low shortages. Food malnourished. the including immunocompromised, chronically are who above) (65 elderly and those the and years children, young and infants are populations vulnerable Most high. be can conditions underlying chronic with people in infection of complicated rate case-fatality the properWithout treatment, Communicable disease epidemiological profile epidemiological disease Communicable indicated. clinically of fever as for management used may be Paracetamol syndrome. Reye as known complication of asevere order risk to avoid <18 in aged the years adolescents and children in avoided be should medications salicylate-containing other and Aspirin treatment. specific not require that does illness self-limiting is a influenza For people, most important. are cases of complicated appropriate treatment and patients of symptomatic isolation recognition, Early Casemanagement Prevention and control measures Little is known about the burden of human influenza influenza of human burden the about known is Little - - 73

Antiviral drugs may be used for specific and early treatment. M2 inhibitors (amantadine or rimantadine for influenza A only if the circulating virus is proven to be susceptible by local surveillance) and neuraminidase inhibitors (oseltamivir or zanamivir for influenza A and B) given within the first 48 hours, may reduce symptoms and virus shedding. Neuraminidase inhibitors also reduce complications that need antibiotics and lead to hospitalization.

Antiviral resistance to treatment is more likely to develop with the use of M2 inhibitors. Therefore, where possible, neuraminidase inhibitors should be selected for treatment provided that they are registered for use in the country. If supplies are limited, antiviral treatment should be reserved for patients at high risk of complication (e.g. the elderly or those with underlying chronic conditions).

Neuraminidase inhibitors seem to have less frequent and less severe side-effects, and are generally better tolerated than M2 inhibitors.

Patients should be monitored for the development of bacterial complications. Only then should antibiotics be administered accordingly. Other supportive therapies such as rehydration may be needed.

Isolation is impractical in most circumstances because of the highly transmissible INFLUENZA (SEASONAL) nature of the virus and the delay in diagnosis. However, ideally all persons admitted to a hospital with a respiratory illness, including suspected influenza, should be placed in single-patient rooms or, if not available, placed in a room with patients I who have a similar illness (cohorting). When cohorting is used, adequate spacing between beds should be provided for droplet precautions. For influenza, isolation should continue for the initial 5–7 days of illness, and possibly longer for patients who are severely immunocompromised and who may be infectious for longer II periods. Both standard and droplet precautions are recommended.

There is no need to adapt dosages for the elderly for the neuraminidase inhibitor oseltamivir. However, dosage should be adapted for people suffering moderate renal failure (creatinine clearance < 30 ml/min). Oseltamivir should not be adminis- III tered to any person who has experienced an allergic reaction to the drug in the past or to pregnant women unless clinical circumstances indicate necessity (note lack of data on safety in this population). Nursing mothers are advised to refrain from breastfeeding during treatment. IV

Communicable disease epidemiological profile 74 CENTRAL AFRICAN REPUBLIC AND CHAD Creatinine clearance (ml/min/1.73m clearance Creatinine Oseltamivir Neuraminidase inhibitor Communicable disease epidemiological profile epidemiological disease Communicable a schedules treatment Amantadine ramantadine and amantadine inhibitors: M2 b a should reducedDoses be for individuals renal with decreased function. by women who are breastfeeding. are who women by used be not should drug This benefits. the outweigh risks potential the where disorders, seizure with patients and drugs neuropsychiatric with treatment receiving patients in caution with used be should Amantadine days. 7 every mg 200 is haemodialysis on patients for dosage recommended The

10–65 years 1–9years (upto 45kg) > 65years Weight and/orage Age Adults Children < 15 200 mg every 7days every mg 200 < 15 days 15–29 alternate and mg on day 100 mg first 200 200 30–50 mg first day and 100 mg each day thereafter

for individuals with decreased renal function as shown below. shown as function renal decreased with individuals for reduced be should Doses >10 years. patients for mg 100 is Japan in and (BNF) Formulary National British the in regimen recommended the e.g. recommended, is mg 100 of dose aonce-daily jurisdictions, some In Children 1year of age or older require weight-adjusted doses. Use inchildren <1year of age has not approved. been > 40 kg > 40 kg 40 to kg > 23 > 15 kg 23 to kg ≤ 15 kg b a

(over 45kg) a treatment schedules treatment 2 ) ) Dose 75 mg twice aday 75 twice mg aday twice mg 60 aday twice 45 mg aday twice mg 30 Dosage 75 mg twice a day aday 75 twice mg to amaximumof150mg/day 5 mg/kg/day intwo divideddosesup 100 mgonce aday Dosage 100 mg twice aday100 mgtwice 5 days 5 days 5 days 5 days Duration 5 days 5 days 5 days Duration 5 days 75

Rimantadine treatment schedules

Age Dosage Duration

1–12 yearsa 5 mg/kg/day in two divided doses up 5 days to a maximum of 150 mg/day

13–64 years 100 mg twice daily 5 days

65 years and over 100 mg once a day 5 days

Doses should be reduced for individuals with decreased renal function. Use with caution in patients with hepatic dysfunction. a Use in children < 13 years of age has not been approved in some countries.

Prevention Nonpharmaceutical public health measures: respiratory etiquette (covering coughs and sneezes) and hand-hygiene are the most feasible measures to prevent the spread of seasonal influenza infection during epidemics.

Vaccination Immunization with influenza vaccine is the primary measure to control seasonal INFLUENZA (SEASONAL) influenza epidemics. The objective of influenza vaccination is to reduce disease morbidity and mortality in groups at risk for severe illness and death (mainly the elderly, infants and young children, and persons with chronic underlying conditions). This may be done through vaccination of at-risk individuals before the I season (if the burden of disease is known), and vaccination of caregivers (to prevent them from becoming the source of infection). Immunization with available inactivated virus vaccines can provide 70–90% protection against illness in healthy young adults when the vaccine antigen closely II matches the circulating strains of virus. A single dose suffices for those with prior exposure to influenza A and B viruses; 2 doses at least 4 weeks apart are essential for children < 9 years old who have not III previously been vaccinated against influenza. Routine immunization programmes should focus efforts on vaccinating those at greatest risk of serious complications or death from influenza and those who might spread influenza (health-care personnel and household contacts of high-risk persons) to high-risk persons. IV Proper health education and planning of yearly vaccination campaigns is recommended.

Communicable disease epidemiological profile 76 CENTRAL AFRICAN REPUBLIC AND CHAD Surveillance of influenza is essential for: essential is of influenza Surveillance details). (see 3for contact Annex for Africa Office Regional WHO the through obtained best may be assistance and Chad, and CAR in point of contact laboratory FLUNET no official is there Currently FLUNET. through to WHO isolation virus and activity disease the to report areencouraged Countries surveillance. international under disease is a Influenza Surveillance by WHO. a year twice reviewed is vaccines influenza seasonal composition of The recommended Communicable disease epidemiological profile epidemiological disease Communicable 19

treatments. treatments. antiviral to recommended resistant of emergence viruses the monitoring subtypes; virus A of influenza new detection early allow and hemispheres southern and the northern for vaccine influenza seasonal annual of the composition the of updating support to strains virus influenza of circulating characterization measures; response and preparedness nonmedical and medical of planned implementation timely allow to the year over pattern epidemiological the in changes of identification interventions); nonmedical and (medical activities response and of prevention (vaccination) planning for yearly order to allow in impact, its and disease theof burden estimate and to groups, risk of identification and seasonality of terms in pattern influenza epidemic of the characterization pdf/2000/wer7535.pdf). (http://www.who.int/docstore/wer/ vaccines inactivated of use the for Recommendations index.html); (http://www.who.int/wer/2005/wer8033/en/ vaccines influenza on paper position WHO en/index.html); (http://www.who.int/csr/disease/influenza/vaccinerecommendations/ influenza seasonal against vaccine of composition recommended the on Update available: are recommendations WHO related following The 19 77 INFLUENZA (AVIAN)

Country-specific disease burden As of August 2008, no outbreaks of highly pathogenic avian influenza A (H5N1) virus infection in poultry or other animals and associated human cases had been reported in the Central African Republic or Chad. Avian influenza A(H5N1) outbreaks in poultry and/or wild birds have been reported in neighbouring countries (Cameroon, Niger, Nigeria and Sudan). One human case of influenza H5N1 has been reported in Nigeria.20

Description Avian influenza or “bird flu” is a contagious disease of animals caused by viruses that normally infect birds. Avian influenza viruses may be transported from farm to farm by the movement of live birds, carcasses, poultry equipment and products, people (contaminated shoes, clothing) and other items contaminated by infected birds or poultry products (vehicles, equipment, feed and cages). Several of the avian influenza viruses have been able to cross the species barrier INFLUENZA (AVIAN) to infect humans and lead to illness. These are the highly pathogenic avian influenza (HPAI) A(H5N1), A(H7N3) and A(H7N7) viruses; and the low pathogenic avian influenza (LPAI) A(H7N2) and A(H9N2) viruses (referring to pathogenicity in chickens). I The low pathogenic forms of avian influenza commonly cause mild symptoms in poultry and may easily go undetected. The highly pathogenic form spreads rapidly through poultry flocks, causing disease affecting multiple internal organs, and has a mortality that may approach 100%, often within 48 hours. Pathogenicity II may differ among different poultry species. Only A(H5N1) and A(H7N7) have been reported to cause human death. However, these and other avian influenza viruses are a cause of concern to human health because of the possibility that they might mutate into a form that spreads easily III among humans, which could lead to an influenza pandemic. The circulation of H5N1 in avian populations and subsequent human infection has led to the declaration of a state of “pandemic alert” by WHO since 2004. IV 20 Further updates on the animal situation may be obtained from OIE (World Organisation for Animal Health) at: http://www.oie.int/wahid-prod/public.php?page=weekly_report_index&admin=0

Communicable disease epidemiological profile 78 CENTRAL AFRICAN REPUBLIC AND CHAD regular information bulletin on the spread of HPAI (FAO) United Nations A(H5N1) of the Organization a produces Agriculture and Food the in animal populations. and humans, besides species mammalian HPAI several A(H5N1) infect may also asymptomatic. but remain contagious and infected maybe Ducks 48 hours. within often approach 100%, maythat a mortality with organs, internal multiple affecting disease experience may Chickens a flock. within rapidly spread HPAI poultry, A(H5N1) can In virus Togo and 2007 2007. case), Ghana (plus 1human 2006 Djibouti 2006, Faso 2007, Burkina Benin 2006, April in d’Ivoire Côte and Sudan and 2006, March in Cameroon 2006, February in and Niger Egypt in birds and/orwild poultry in A(H5N1) confirmed also was HPAI 2006. February early in Nigeria in northern farms poultry in confirmed was of outbreak A(H5N1)Africa HPAI animal in first The Africa. and Europe Asia, central in HPAI to poultry then, and A(H5N1) birds Since to wild spread has Viet Nam). Thailand, (China, countries several in end of 2003 at the infections human followed by concurrent 2003, in Asia South-East in again occurred Outbreaks poultry. in of outbreaks aperiod 6deaths), during including 1997 (18 in of China Region cases Administrative Hong Kong in Special reported with HPAIA(H5N1) infection was case of human laboratory-confirmed first The Communicable disease epidemiological profile epidemiological disease Communicable 21

ag/againfo/subjects/en/health/diseases-cards/avian_update.html). http://www.fao.org/ (HPAI) reduction risk influenza avian pathogenic highly Pro-poor 2004_10_29/en/); (http://www.who.int/csr/disease/avian_influenza/labstudy_ findings main ducks: domestic in H5N1 viruses of study Laboratory (http://www.who.int/csr/don/2004_10_29/en/index.html); ducks domestic of role altered Asia: in situation – influenza Avian who.int/csr/disease/avian_influenza/ai_timeline/en/index.html); (http://www. events major of timeline influenza: H5N1 avian also: See programmes/en/empres/home.asp. http://www.fao.org/ag/againfo/ at page AI EMPRES the from obtained be may information Further

21 79 INFLUENZA (HUMAN A(H5N1) INFECTION)

Country-specific disease burden No cases have been reported in Central African Republic and Chad to date.

Description Case definition Clinical description22 Common initial symptoms are fever (usually > 38 °C) and cough, plus signs and symptoms of lower respiratory tract involvement including dyspnoea. Upper respiratory tract symptoms such as sore throat and coryza are present only sometimes. Gastrointestinal symptoms were frequently reported in cases in Thailand and Viet Nam in 2004 but less frequently since 2005. Lower respiratory tract manifestations often develop early in the course of illness and clinically apparent pneumonia with radiological changes has usually been found at presentation. The disease usually progresses rapidly and often progresses to an acute respiratory distress syndrome. Median times of 4 days from the onset of illness to presentation INFLUENZA (HUMAN A(H5N1) INFECTION) at a health-care facility and 9–10 days until death in fatal cases has been reported. Atypical presentations have included fever and diarrhoea without pneumonia, and fever with diarrhoea and seizures progressing to coma. Common laboratory I findings include leukopenia, lymphopenia, mild-to-moderate thorombocytopenia, and elevated levels of aminotransferases. Lymphopenia and increased levels of lactate dehydrogenase at presentation have been associated with a poor prognosis. Of 6 infected pregnant women, 4 have died, and the 2 survivors had a spontaneous abortion. Mild illnesses such as upper respiratory illness without clinical or II radiological signs of pneumonia have recently been reported more frequently in children. Limited seroepidemiological studies conducted since 2004 suggest that subclinical infection appears uncommon. The overall case-fatality ratio is high (63% as of July 2008). III

22 Updated WHO guidelines on the clinical management of human infections due to avian A(H5N1) virus were published in August 2007. Subsequently, a review article on human infection with avian influenza A(H5N1), that contains additional information, was published in January 2008 by the Writing Committee of the Second World Health Organization Consultation, on Clinical aspects of human infection with avian IV influenza A(H5N1) virus (Update on avian influenza A(H5N1) virus infection in humans. New England Journal of Medicine, 2008, 358:261–273).

Communicable disease epidemiological profile 80 CENTRAL AFRICAN REPUBLIC AND CHAD Case classification Case Communicable disease epidemiological profile epidemiological disease Communicable

results are accepted by WHO as confirmatory: confirmatory: as by WHO accepted are results H5N1 test whose laboratory influenza or international regional anational, in conducted results positive following one of the AND or probable case pected forsus a criteria the WHO): meeting person a case H5N1 (notify Confirmed Probable H5N1 case (notify WHO): (notify H5N1Probable case onset: symptom breathing or difficulty of breath shortness cough, fever (> )and 38ºC with illness ratory lower acute respi unexplained with presenting aperson H5N1 case: Suspected forH5N1 infection. possible to investigate decided have authorities whomhealth public aperson investigation: Person under

place, and exposure to a probable or confirmed H5N1 case. H5N1 to aprobable or confirmed exposure and place, by time, linked epidemiologically to be considered is who illness respiratory acute unexplained an of dying person 2: a definition H5N1Probable case fordence H5N1 infection. evi laboratory insufficient but infection A influenza an of confirmation or (b) tachypnea); laboratory severe positive (hypoxemia, failure piratory of res plus evidence radiograph on chest pneumonia acute of an evidence and case pected forsus a criteria the meeting person 1: a definition H5N1Probable case setting. or other alaboratory in H5N1 virus of containing or suspected human) (animal samples handling (e.g. birds or pig); cat or wild poultry than other animal infected H5N1 aconfirmed with contact close month; last the in or confirmed suspected have been or humans animals in H5N1 infections where area an in products poultry of raw or undercooked consumption month; last the in or confirmed suspected have been or humans animals in whereH5N1 infections area an in faeces by their ments contaminated or to environ remains or their birds or wild for consumption) to poultry preparation butchering, plucking, slaughtering, (e.g. handling, exposure case; H5N1 probable,or confirmed asuspected, is who touching) or with, for, (e.g. speaking aperson 1m) caring with (within contact close and one or more of the following exposures in the 7 days prior to 7days the in exposures one or following more of the one of the following additional criteria: (a) infiltrates or (a) criteria: infiltrates additional following one of the ------81

Isolation of an H5N1 virus. Positive H5 PCR results from tests using two different PCR targets, e.g. primers specific for influenza A and H5 HA. A four-fold or greater rise in neutralization antibody titre for H5N1 based on testing of an acute serum specimen (collected 7 days or less after symptom onset) and a convalescent serum specimen. The convalescent neutralizing antibody titre must also be 1:80 or higher. A microneutralization antibody titre for H5N1 of 1:80 or greater in a single serum specimen collected at day 14 or later after symptom onset and a positive result using a different serological assay, for example, a horse red blood cell haemagglutination inhibition titre of 1:160 or greater or an H5- specific western blot positive result.

Application of the H5N1 case definitions The case definitions apply to the current phase of pandemic alert (phase 3) for H5 N1 and may change as new information about the disease or its epidemiology becomes available. National authorities should formally notify only probable and confirmed H5N1 cases to WHO. The case definitions for persons under investi-

gation and suspected cases have been developed to help national authorities in INFLUENZA (HUMAN A(H5N1) INFECTION) classifying and tracking cases. The case definitions are not intended to provide complete descriptions of disease in patients but rather to standardize reporting of cases. I In clinical situations, decisions concerning treatment, care or triage of persons who may have H5N1 infection should be based on clinical judgment and epidemiological evidence, and not on adherence to case definitions. While most patients with H5N1 infection have presented with fever and lower respiratory complaints, the clinical spectrum is broad.23 II A case of human influenza caused by a new subtype should be immediately notified to WHO under the International Health Regulation (IHR). For human infection with HPAI A(H5N1) virus, WHO has developed standardized case definitions to facilitate: III

1. reporting and classification of human cases of H5N1 infection by national and international health authorities; IV 23 See: WHO case definitions for human infections with influenza A(H5N1) virus (http://www.who.int/csr/ disease/avian_influenza/guidelines/case_definition2006_08_29/en/index.html).

Communicable disease epidemiological profile 82 CENTRAL AFRICAN REPUBLIC AND CHAD oughly will kill the virus. the kill will oughly thor Cooking virus. the not kill does Freezing ill. toducks) be may not appear (especially birds infected etc.). some cases, In environment, tools, (hands, practices hygiene poor are there if especially forinfection, possible factors risk considered be also should birds of infected eggs of and raw meat or consumption manipulation Unprotected environments. contaminated with probably contact and birds infected of butchering and plucking slaughtering, touching, through may occur infection Human virus. the may contain blood its and animal of the parts All faeces. their in and secretions respiratory their in quantities large in virus the shed also birds Infected birds. infected to exposure after to be reported is infection human Most Mode of transmission 3. 2. Communicable disease epidemiological profile epidemiological disease Communicable 24 specimens. apatient’s in respiratory antigen of virus detection upon based illness of the onset after 27 days been has period documented longest use). (i.e. The patients corticosteroid immunosuppressed longer even in perhaps 3weeks, long for as as infectious may remain patients that suggest data Limited period Communicability days. 3–5 approximately to be appears period incubation the probably occurred, has transmission human human-to- limited which in clusters In 2–5 days. cases many in or less, 7 days be to appears generally period incubation the poultry, infected to exposure After Incubation period them). with abedroom or patient sharing of the care (for taking when example infection the contact(s) the and patient to whom he/she ill transmitted aseverely between contact prolonged unprotected of intimate context the in to have occurred likely is pected, sus when transmission, Human-to-human 2007). in China and Pakistan 2006, in Indonesia 2004, in Thailand probable in as documented and place and time in related (cases clusters several in suspected was transmission Human-to-human

5keys/en/index.html). 5keys/en/index.html). (http://www.who.int/foodsafety/consumer/ food safer to keys five disease: foodborne of Prevention See comparability of data across time and geographical areas. geographical and time across of data comparability purposes; for communication of language standardization 24 - - 83 Epidemiology General As of 19 June 2008, a total of 385 laboratory confirmed cases (243 fatal) had been reported from 15 countries since November 2003, including Djibouti, Egypt and Nigeria.25

Risk factors for increased burden No predisposing factors for infection have been identified that can explain the low incidence of H5N1 observed in humans to date, despite extensive exposure. However, the risk for infection through inappropriate handling of sick birds remains. So far, no domestic mammals have been identified as a source of infection. However, cats and dogs can become infected. Population movement increases the risk of importation from neighbouring countries. Concern that additional human cases may occur in affected parts of Africa is high given the close contact between people and poultry (estimated 1.1 billion chickens on the African continent, mostly in backyard farming systems). Poor access to health services. Throughout much of Africa, rapid detection and investigation of outbreaks is hampered by the absence of an early warning system INFLUENZA (HUMAN A(H5N1) INFECTION) for avian influenza in animals or humans, inadequate diagnostic capacity, and difficulties in shipping specimens, both locally and internationally, for diagnostic confirmation. I Food shortages increase the risk of importation from neighbouring countries.

Prevention and control measures II Case management The patient should be isolated and strict infection control measures applied. Standard and droplet precautions should be the minimum level of precautions to be used in all health-care facilities when providing care for patients with acute III febrile respiratory illness, regardless of whether AI infection is suspected. The most critical elements of these precautions include facial protection (nose, mouth and eyes if sprays/splashes of secretions are anticipated) and hand-hygiene. IV 25 Cumulative number of confirmed human cases of avian influenza a/(h5n1) reported to WHO (http://www. who.int/csr/disease/avian_influenza/en/).

Communicable disease epidemiological profile 84 CENTRAL AFRICAN REPUBLIC AND CHAD especially in patients with pneumonia or progressive disease. disease. or progressive pneumonia with patients in especially basis, on acase-by-case considered may be to adamantanes) susceptible to be likely are whereA(H5N1) (in countries viruses or rimantadine amantadine with therapy combination for possibly adults), and longer duration daily 150 twice mg twofold dosage higher including (i.e. treatment, ofoseltamivir regimens Modified of illness. stage at alater care to clinical presents patient the when warranted also is oseltamivir with treatment that indicates for aprolonged to replicate period A(H5N1) continues the that virus evidence Furthermore, mortality. A(H5N1) infection-associated reducing in ness virus useful its suggest disease of the stages early the in oseltamivir with on treatment data Observational treatment. antiviral recommended primary the is Oseltamivir diagnosis. alternative of an absence the in of notion exposure) and presentation (clinical infection of suspected case in administrated be should antivirals Treatment with mask. medical of a instead respirator equipment (PPE aparticulate include protective )should personal performed, are procedures aerosol-generating If anticipated. are splashes if protection eye and masks medical gloves, clean of gowns, use hand-hygiene, adequate comprise which patients, AI-infected or confirmed of suspected care patient for be routine applied should droplet precautions plus Thereforestandard Communicable disease epidemiological profile epidemiological disease Communicable 26 A(H5N1) infection. with patients virus in coinfection bacterial suspected for usage antibiotic to guide used be should studies of microbiological results the available, When guidelines. evidence-based to published according pneumonia for community-acquired appropriate initially is treatment antibiotic present, However, is not used. be pneumonia should when chemoprophylaxis Antibiotic infection. opportunistic including patients, A(H5N1) in events adverse serious virus-infected in result may corticosteroids or dopamine). Prolonged or high-dose epinephrine phrine, norepine e.g. pressure, blood or increases maintains and vasoconstriction causes that agent (the vasopressors requiring insufficiency adrenal suspected with shock routinely, but for notconsidered used may septic be be should Corticosteroids therapy supportive Additional

en/index.html). en/index.html). (http://www.who.int/csr/disease/avian_influenza/guidelines/infectioncontrol1/ facilities health-care for guideline control infection interim WHO A(H5N1), humans: in influenza including influenza, Avian See: 26

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Monitoring of oxygen saturation should be performed whenever possible at presentation and routinely during subsequent care (e.g. pulse oximetry, arterial blood gases), and supplemental oxygen should be provided to correct hypoxemia. Therapy for A(H5N1) virus-associated ARDS should be based on published evidence-based guidelines for sepsis-associated ARDS, specifically including lung protective mechanical ventilation strategies.27

Management of contacts Chemoprophylaxis: antiviral chemoprophylaxis should generally be considered according to the risk stratification:

High-risk exposure groups are currently defined as household or close family contacts of a strongly suspected or confirmed H5N1 patient, because of potential exposure to a common environmental or poultry source as well as exposure to the index case. Moderate-risk exposure groups are currently defined as personnel involved in handling sick animals or decontaminating affected environments (including animal disposal) if personal protective equipment may not have been used properly. INFLUENZA (HUMAN A(H5N1) INFECTION) Individuals with unprotected and very close direct exposure to sick or dead animals infected with the H5N1 virus or to particular birds that have been directly implicated in human cases. I Health-care personnel in close contact with strongly suspected or confirmed H5N1 patients, for example during intubation or performing tracheal suction- ing, or delivering nebulized drugs, or handling inadequately screened/sealed body fluids without any or with insufficient personal protective equipment. This group also includes laboratory personnel who might have unprotected II exposure to virus-containing samples. Low-risk exposure groups are currently defined as health-care workers not in close contact (distance greater than 1 m) with a strongly suspected or confirmed H5N1 patient and having no direct contact with infectious material from that III patient; health-care workers who used appropriate personal protective equipment during exposure to H5N1 patients; personnel involved in culling non-infected or likely non-infected animal populations as a control measure; personnel IV 27 See: Clinical management of human infection with avian influenza A(H5N1) virus (http://www.who.int/csr/ disease/avian_influenza/guidelines/clinicalmanage07/en/index.html).

Communicable disease epidemiological profile 86 CENTRAL AFRICAN REPUBLIC AND CHAD Where neuraminidase inhibitors are not available: are inhibitors neuraminidase Where Where neuraminidase inhibitors are available: are inhibitors neuraminidase Where developed. was exposure for categorization athree-tier-risk limited, is availability wheretheir particularly for chemoprophylaxis, drugs of antiviral use the prioritizing in To countries assist Communicable disease epidemiological profile epidemiological disease Communicable

up to 7 days after the last exposure and consists of monitoring temperature temperature of monitoring consists and exposure last the after up to 7days of cases contacts for close recommended is monitoring mendation). Health (strong recom for chemoprophylaxis not administered be should amantadine disorders, or seizure neuropsychiatric or with medication neuropsychiatric receiving individuals and function renal impaired elderly, the In with people (strong recommendation).for chemoprophylaxis should not be In and rimantadine pregnant administered women, amantadine (weak recommendation). drugs to these susceptible to be or likely known is virus the show that data surveillance local if for chemoprophylaxis administered be might or rimantadine amantadine groups, exposure or moderate-risk high- In (strong recommendation). chemoprophylaxis as not administered be should or rimantadine Amantadine (strong recommendation). chemoprophylaxis for or zanamivir oseltamivir not low-risk receive should group the women in (weak recommendation). Pregnant for chemoprophylaxis administered be probably not should or zanamivir oseltamivir groups, low-riskIn exposure way (weak recommendation). same the in used be might (weak recommendation); zanamivir exposure last the for 7–10 continuing after chemoprophylaxis, days as administered be might women, oseltamivir pregnant including groups, exposure moderate-risk In alternative. way (strong an as recommendation) same the in used be could (strong recommendation); zanamivir exposure for 7–10 last the continuing after chemoprophylaxis, days as administered be should women, oseltamivir pregnant ,including groups exposure high-risk In administered for chemoprophylaxis (weak recommendation). for chemoprophylaxis administered not be should rimantadine and amantadine groups, low-riskIn exposure (including animal disposal), who used proper personal protective equipment. protective proper personal used who disposal), animal (including environments affected or decontaminating animals sick handling in involved

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and symptoms such as cough. It is also required of health-care professionals who have had contact with patients, their body fluids and secretions, their room or potentially contaminated equipment. Quarantine of close contacts of suspected cases during the health-monitoring period is not necessary unless there is suspicion of human-to-human transmission.28

Prevention Reduce human exposure to H5N1. For individuals, the risk of bird-to-human transmission of avian influenzas can be reduced through proper precautions; hand-hygiene, hygiene precautions when handling birds (especially when sick or dead) or their products for consumption or when in environments that may be contaminated with faeces of sick birds. In communities, the risk may be reduced by control of spread of the infection in the animal population, and reduction of human contact with infected birds. Human-to-human transmission of H5N1 may be prevented through early detection and isolation of suspected and confirmed cases in a dedicated health-care facility and application of infection-control measures.

Food safety precautions29 Humanitarian agencies may: INFLUENZA (HUMAN A(H5N1) INFECTION) Contribute to reducing human exposure to avian influenza A(H5N1) by inform- ing communities affected by AI in birds of risks of exposure to sick or dead animals (particularly poultry/birds) and of strategies for risk avoidance including avoiding close contact with sick/dead animals and their remains, or with I environments contaminated by their faeces, avoiding consumption of raw or undercooked poultry products, and performance of hand-hygiene after handling, slaughtering, plucking, butchering or preparing poultry/wild birds. Ensure that information is provided in close coordination with the animal II and public health authorities to prevent discrepancies in preventive messages. Promote immediate reporting to relevant local and national animal health authorities of unexpected illness/deaths in birds/animals. Investigate people developing unexplained acute respiratory illness after ex- III posure to ill/dead birds for H5N1 infection.

28 See: WHO Rapid advice guidelines on pharmacological management of humans infected with avian influenza A(H5N1) virus (http://www.who.int/csr/disease/avian_influenza/guidelines/pharmamanagement/en/ index.html); WHO guidelines for investigation of human cases of avian influenza A(H5N1) (http://www. IV who.int/csr/resources/publications/influenza/WHO_CDS_EPR_GIP_2006_4/en/index.html). 29 http://www.who.int/foodsafety/fs_management/No_07_AI_Nov05_en.pdf.

Communicable disease epidemiological profile 88 CENTRAL AFRICAN REPUBLIC AND CHAD 7. 6. 5. 4. necessary. as action and planning further relevant and management, case adequate and rapid as ensure to so virus influenza avian an with infection cion of human upon suspi immediately informed be also should WHO and authorities Relevant birds. affecting if especially animals, in illness unexplained severe or die-off pect anysus of case in immediately notified are authorities relevant that It important is virus. influenza or a novelpandemic influenza of H5N1 avian humans in cases/clusters suspected initial to response early and notification detection, early the facilitate should agencies Humanitarian strengthened. be should system early-warning The Surveillance sanitation. and water security, food livelihoods, agriculture, as such field programs into other activities these of integration through efforts such support might Agencies Communicable disease epidemiological profile epidemiological disease Communicable 3. 2. 1. References influenza/travel2005_11_3/en/print.html). influenza/travel2005_11_3/en/print.html). (http://www.who.int/csr/disease/avian_ influenza H5N1 avian pathogenic highly of outbreaks experiencing countries to going and from coming travellers to relating recommendations WHO foodsafety/micro/avian2/en/index.html). (http://www.who.int/ considerations safety food Asia: in areas rural A(H5)in influenza Avian ). who.int/foodsafety/fs_management/No_07_AI_Nov05_en.pdf implications safety food humans: in and poultry in outbreaks influenza H5N1 avian pathogenic Highly Network. Authorities Safety Food International publications/surveillance/WHO_CDS_EPR_ARO_2006_1/en/index.html). infection virus A(H5N1) influenza avian of diagnosis the for specimens shipping and preserving Collecting, WHO_CD_EPR_2007_6/en/index.html). health care health in diseases respiratory acute pandemic-prone and of epidemiccontrol and prevention Infection influenza/guidelines/high_contact_protection/en/index.html). (http://www.who.int/csr/disease/avian_ 2008 February guidance, pre-existing of consolidation H5N1: influenza avian by affected areas in contact poultry high with individuals of Protection en/index.html). (http://www.who.int/csr/disease/avian_influenza/guidelines/aidememoireinfcont/ 2008 April Aide-memoire, facilities. health-care in influenza avian for recommendations Infection-control . WHO interim guidelines, June 2007 (http://www.who.int/csr/resources/publications/ . Guide for field operations, October 2006 (http://www.who.int/csr/resources/ 2006 October operations, forfield . Guide , November 2005 (http://www. 2005 , November - - 89

8. Questions and answers on potential transmission of avian influenza (H5N1) through water, sanitation and hygiene and ways to reduce the risks to human health (http://www.who.int/water_ sanitation_health/emerging/en/). 9. Review of latest available evidence on risks to human health through potential transmission of avian influenza (H5N1) through water and sewage (http://www.who.int/water_sanitation_ health/emerging/avianflu/en/index.html; http://www.who.int/water_sanitation_health/ emerging/en/). INFLUENZA (HUMAN A(H5N1) INFECTION)

III

Communicable disease epidemiological profile 90 CENTRAL AFRICAN REPUBLIC AND CHAD central Chad along the Chari river. Chari the along Chad central south- in and area N’Djamena zones), the in desert and (subdesert country the of and north-east the north in foci 1976.several are in There 1975 164 cases and 121 in 836 include 1968, in cases Reported minimal. are recentdata although thought, previously more than is frequent leishmaniasis cutaneous Chad, In to Sudan. border close eastern on the Teguine camp at the cases of 200 about outbreak an in Chad 2007, October–November assisted In WHO Chad leishmaniasis. cutaneous onfrom CAR available information Thereis noepidemiological recent Central African Republic Country-specific disease burden MUCOSAL) (CUTANEOUS AND LEISHMANIASIS Communicable disease epidemiological profile epidemiological disease Communicable criteria Laboratory disfiguring. very be can lesions.and tissues Sequelae may involve nasopharyngeal mucosal cause and disseminate can some strains may occur; forms atypical Other scar. adepressed leaves –it typically before healing time for avariable stage this in remain sore indolentmay The ulcer. an to become may enlarge and site of inoculation the at may appear A nodule sites. common the most are and legs arms neck, face, The body. of the parts on uncovered typically lesions, of one or more skin Appearance description Clinical definition Case zone. subdesert the (Chad) in Abèchè focus duboscqi Phlebotomus vector insect the of The presence genus Leishmania of the species by several caused disease Protozoan Infectious agent Description

parasites in the case of mucosal leishmaniasis; of mucosal case the in parasites lesion); scarce the from very or culture smear (stained parasitology positive has been recorded in the the in recorded been has .

positive PCR; mucosal leishmaniasis only: positive serology (immunofluorescent assay, ELISA)

WHO operational definition. A case of cutaneous leishmaniasis can be defined as a person showing clinical signs (skin or mucosal lesions) with parasitological confirmation of the diagnosis (positive smear or culture) and/or positive PCR and/or, for mucosal leishmaniasis only, serological diagnosis.

Mode of transmission From the animal reservoir (in some cases from humans) through the bite of infective female sandflies (phlebotomines). There are two modes of transmission: (1) anthroponotic – where the vector feeds on an infected person and then feeds on an uninfected individual, with a cluster effect in transmission; (2) zoonotic, when the vector feeds on an infected animal and subsequently feeds on another potential host, eventually a human. Overcrowding and inadequate sanitation increase the risk of infection. The risk of anthroponotic cutaneous leishmaniasis epidemics is higher in camp settings.

Incubation period MUCOSAL) LEISHMANIASISAND (CUTANEOUS At least one week but up to many months.

Communicability period I Not directly transmitted from person to person, but infectious to sandflies as long as parasites remain in lesions of untreated cases, which usually lasts from a few months up to two years. II Epidemiology General Leishmaniasis is a neglected tropical disease that has demonstrated that refugee III camps may act as amplification sites, firstly in the camp populations and then, once they have repatriated, in their country of origin. For example in 1992, an outbreak of anthroponotic cutaneous leishmaniasis occurred in refugee camps in the North West Frontier province of Pakistan. When the refugees were repatriated, IV the disease was imported into Afghanistan resulting in 1.5 million cases (70 000 cases annually).

Communicable disease epidemiological profile 92 CENTRAL AFRICAN REPUBLIC AND CHAD tings, including rural and, less frequently, urban areas. frequently, urban less and, rural including tings, set eco-epidemiological of a variety huge with countries are endemic 82 There distribution Geographical essential. are therapy of specific institution and of cases detection Early asymptomatic. may be infections whom many among adults, in than children young more in is severe disease the areas, endemic In camps. in breaks out with associated not is often latter the more and common far is former the visceral, and cutaneous disease, of the forms two the Of poverty. and sanitation HIV/AIDS, poor malnutrition, refugees, IDPs, with associated is Leishmaniasis Communicable disease epidemiological profile epidemiological disease Communicable Americas). the in leishmaniasis (e.g. lesions mucocutaneous cutaneous prevents development of rapid invasive therapy appropriate, and detection Early Casemanagement Prevention and control measures sites. for vector-breeding factor arisk are sanitation poor and water safe of Lack of immunosuppression. a result shortages Food transmission. to reduce paramount are ment of cases contain and detection factor, early as arisk also is services health to access Poor reservoir. the as act humans Overcrowding to sandflies. of exposure risk the increases movement Population Risk factors for increased burden cases. all in performed be should testing agent by laboratory disease of the Investigation areas. exposed in ulcers of suffering people number the in rise sudden and unusual an is there when suspected be should epidemic an threshold, epidemic of aclear absence the In thresholdAlert species. sandfly and geography on the –depending Seasonal Seasonality facilitates transmission. The vector has a short flight range, and range, flight short a has The vector transmission. facilitates . Malnutrition may increase susceptibility to cutaneous disease as as disease to cutaneous susceptibility may increase . Malnutrition - - - 93

Epidemic control In areas of high incidence, intensive efforts should be made to control the disease by providing diagnostic and drug facilities and through appropriate measures directed against phlebotamine sandflies and the mammalian reservoir hosts.

Prevention The main measures are case management, environmental management and vector control.30 LEISHMANIASIS (CUTANEOUS AND MUCOSAL) LEISHMANIASISAND (CUTANEOUS

III

30 See: http://www.who.int/leishmaniasis/en/.

Communicable disease epidemiological profile 94 CENTRAL AFRICAN REPUBLIC AND CHAD level) parasitological confirmation of the diagnosis. In endemic malarious areas, areas, malarious endemic In diagnosis. the of confirmation level) parasitological level) and/or (when at central feasible geographical (at peripheral serological with fever,loss) weight and splenomegaly (prolonged signs irregular clinical showing (VL) aperson is leishmaniasis of visceral Acase definition. operational WHO the N’Djamena central hospital. central N’Djamena the from were reported cases 1973, human and 1966 64 Between available. are data and no recent fragmentary, is knowledge Epidemiological endemic. is disease The Chad leishmaniasis. visceral on CAR from available information epidemiological is no There recent Central African Republic Country-specific disease burden (VISCERAL) LEISHMANIASIS Communicable disease epidemiological profile epidemiological disease Communicable criteria Laboratory symptoms. main as loss weight and splenomegaly origin, fever of unknown prolonged irregular with illness An description Clinical definition Case donovani L. to be likely most is Intracellular Infectious agent Description

Positive PCR. sticks). dip immunocromatography test, agglutination direct assay, (immunofluorescent ELISA, Positive serology taken. be not normally should dangerous, too biopsies, liver Spleen or material. biopsy or aspirated from organism of the or culture blood node, bone marrow, lymph from smears Giemsa-stained Positive parasitology, Protozoa genus Leishmania genus is the suspected vector. suspected the is . P. orientalis . The parasite has not been identified, but has not been identified, . Theparasite 95 visceral leishmaniasis to be suspected when fever lasts for more than two weeks and no response has been achieved with antimalarial drugs (assuming drug-resistant malaria has also been considered).

Mode of transmission There are two modes of transmission:

1. Anthroponotic – where the vector feeds on an infected person and then feeds on an uninfected individual. If a case is living in close proximity to others, the risk of catching the disease is 26 times higher than normal. People living just 50 m from a case have only a three times risk of infection, hence there is a significant cluster effect. In the 1990s, the Nuer tribe in Sudan was decimated, and 30% of its population (100 000) died. Overcrowding and inadequate sanitation increase the risk of infection. The risk of epidemics of leishmaniasis is high among immunodepressed groups. 2. Zoonotic transmission takes place when the vector feeds on an infected animal (normally a canid) and subsequently feeds on another potential host.

In anthroponotic foci of visceral leishmaniasis, humans are the sole reservoir and

transmission occurs from person to person through the sandfly bite. Anthroponotic LEISHMANIASIS(VISCERAL) visceral leishmaniasis is the main cycle recognized in East Africa and, by extension, the focus in Chad could be similar. Chacals, vervets, dogs and other mammals have been identified as secondary reservoirs in Sudan. In zoonotic visceral leishmaniasis foci, such as in northern Africa, the cycle is from the animal reservoir I through the bite of infected sandflies, with dogs being the main reservoir.

Incubation period Generally 2–6 months. Range: 10 days to several years. II

Communicability period Not transmitted from person to person but infectious to sandflies as long as parasites persist in the circulating blood or skin of the mammalian reservoir host. III

Epidemiology General IV Leishmaniasis is a neglected tropical disease which has demonstrated that poor housing, poverty, IDPs, refugees, displaced populations, malnutrition and immuno-

Communicable disease epidemiological profile 96 CENTRAL AFRICAN REPUBLIC AND CHAD coinfected patients. coinfected HIV and persons, displaced and malnourished workers, seasonal children, are groups affected main The described. have been cases leishmaniasis visceral radic spo only Chad, In Africa. eastern in affected most countries the are Somalia and Uganda Kenya, Ethiopia, Sudan, countries. 64 present in is leishmaniasis Visceral distribution Geographical death. and disease to severe susceptible particularly are ages of all malnourished the and elderly, The the weak asymptomatic. may be infections whom many among adults, in than children young more in is severe disease the areas, endemic In camps. refugee in more frequently occur outbreaks leishmaniasis cutaneous although of origin, country their in once repatriated, then, and populations camp the in firstly transmission, inleishmaniasis effect cluster the considering sites fication play ampli arole as could camps Refugee factors. risk increasing suppression are Communicable disease epidemiological profile epidemiological disease Communicable sites. for breeding vector factor arisk are sanitation poor and water safe of Lack patients. malnourished in observed are of More leishmaniasis forms severe of immunosuppression. result a as leishmaniasis of contracting risk the increases Malnutrition shortages. Food transmission. to reduce paramount are of cases containment and detection factor, early as arisk is services health to access Poor foci. anthroponotic in reservoir the as act humans Overcrowding to sandflies. of exposure risk the increases movement Population Risk factors for increased burden testing. agent by laboratory disease of the to investigation lead should scenarios above of the Any syndrome. fever, wasting and splenomegaly non-malarial by high caused or deaths of cases new number the in rise sudden and unusual an is there if suspected be should epidemic an threshold, epidemic of aclear absence the In thresholdAlert species. sandfly to the according Seasonal Seasonality facilitates transmission. The vector has a short flight range, and range, flight short a has The vector transmission. facilitates - - 97 Prevention and control measures Case management Early detection and appropriate, rapid therapy prevents development of visceral severe forms and eventual death.31

Epidemic control In areas of high incidence, intensive efforts should be made to control the disease by providing rapid diagnostic tests and chemotherapy, and through appropriate measures directed against phlebotamine sandflies and the mammalian reservoir hosts if appropriate.

Prevention The main measures are case management, environmental management and vector control.32

LEISHMANIASIS(VISCERAL)

III

IV 31 See: http://www.who.int/leishmaniasis/resources/documents/VL_NMR_1107_ok.pdf. 32 See: http://www.who.int/leishmaniasis/en/.

Communicable disease epidemiological profile 98 CENTRAL AFRICAN REPUBLIC AND CHAD 000 population). 10 000 per of 2–2.5 rates prevalence (with one is of them south to the CAR borders that Congo of the Republic Democratic but the countries, remaining six not one of these is CAR level. national at the population 10 per 000 of 1case target elimination an have to reach yet 1.1–1.5 countries was six Globally, 2005 population. 10 per 000 of as Prevalence country. of the some areas in remain still of endemicity Pockets Central African Republic Country-specific disease burden LEPROSY Communicable disease epidemiological profile epidemiological disease Communicable 33 (clinical) classification Case includes: definition case tional opera The sensation. lesion(s)of loss definite skin or reddish with hypopigmented showing person asa defined is of leprosy case a definition: operational WHO definition Case Bacterium: Infectious agent Description level. national at the population 10 per 000 of 1case target elimination the have not reached yet that countries not six is one of Chad the scarce. are Data population. 10 per at 1or less 000 estimated was for Chad prevalence of 2005, As Chad

WM2.pdf; http://www.who.int/lep/situation/prevalence/en/index.html. WM2.pdf; http://www.who.int/lep/situation/PrateEnd2005v2- http://www.who.int/lep/situation/BurdenEnd2005.pdf; Multibacillary leprosy (MB): more than 5 patches or lesions on the skin. or on lesions the 5patches (MB): leprosy more than Multibacillary (PB): leprosy 1–5 skin. or on lesions the patches Paucibacillary of treatment. course afull completed have who previously cases relapsed disease; of active signs with defaulters retrieved Mycobacterium leprae Mycobacterium 33 .

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Laboratory criteria for confirmation: in practice, laboratories are not essential for the diagnosis of leprosy.

Mode of transmission Not clearly established: organisms probably enter the human body through the mucous membranes of the upper respiratory tract and possibly through broken skin, during close and frequent contact with untreated infected people.

Incubation period Nine months to 40 years (average 5–7 years).

Communicability period If not treated: transmission is possible, the risk being higher for contacts of MB cases than of PB cases; Treated: infectivity disappears after a few doses of treatment with multidrug therapy (MDT).

Epidemiology General LEPROSY During the 1980s, most African countries were highly endemic for leprosy, with an average national prevalence exceeding 2% (leprosy is considered a public health problem when the prevalence is higher than 1 case per 10 000 population). Global I annual new case detection continues to show a sharp decline, falling by over 40 000 cases (13.4%) during 2006 compared with the new cases reported during 2005. The burden of the disease for the four most endemic countries (Brazil, Democratic Republic of the Congo, Mozambique and Nepal) represents about 23% of annual II global new case detection and 34% of global registered cases end 2006/early 2007. The WHO African Region made substantial progress towards the elimination of leprosy during the 1990s. These efforts are still ongoing in order that the elimination of leprosy may be achieved in each country. The elimination of leprosy is III a key component of poverty alleviation, and all countries show strong political commitment and give high importance and priority to the elimination of this secular and stigmatizing disease. The diagnosis and treatment of leprosy are easy, and most endemic countries are IV striving to fully integrate leprosy services into existing general health services. This is especially important for those underserved and marginalized communi-

Communicable disease epidemiological profile 100 CENTRAL AFRICAN REPUBLIC AND CHAD Leprosy situation, end 2006 end situation, Leprosy disease. the eliminating to close are remain that few countries the and elimination, have now achieved countries endemic highly leprosy. from Previously at risk most the are that ties Communicable disease epidemiological profile epidemiological disease Communicable transmission. of risk the and disease theof burden increases security) financial, (geographical, services health accessing and methodology diagnostic in difficulties by caused treatment and diagnosis of early Lack measures. control important most the are cases of treatment and Prompt identification services. health to access Poor Overcrowding cases. with of contact risk the increases potentially movement Population Risk factors for increased burden potential. epidemic no has disease The Recent epidemics registered. been has No seasonality Seasonality below 1. are countries African other all in Rates of 1.1–1.5. have rates of Tanzania United Republic the and Republic African Central of 1.5–2; and rates has Congo of the Republic Democratic the population; 10 000 per cases of 2–2.5 rates have prevalence Mozambique and Madagascar Africa, In distribution Geographical http://www.who.int/wer/2007/wer8225.pdf. 82(25):225-232; 2007, Record, Epidemiological Weekly Source: (excluding Europe) (excluding region WHO Global total Global Americas Africa Western Pacific Western Eastern Mediterranean Mediterranean Eastern South-East Asia South-East increases the risk of contact. risk the increases per 10 000 population 10 000 per prevalence Registered 29 548 (0.55) 548 29 64 71564 (0.76) 116 (0.7) 663 3 986 (0.09) 3986 9 805 (0.06) 9 805 224 717 2004 (per 100 000 population 000 100 (per 2004 in detected cases new of Number 174 118 (10.51) 47 612 (5.58) 27 902 (5.15)27 902 6124 (0.35) 3261 (0.71) 259 017 101 Prevention and control measures Case management Treatment by MDT should be given according to the case classification, as shown below.

MB leprosy (the standard regimen is a combination of the following drugs for 12 months): Adults – rifampicin: 600 mg once a month; – dapsone: 100 mg once a day; – clofazimine: 50 mg once a day and 300 mg once a month. Children should receive appropriately scaled-down doses (in child blister- packs). PB leprosy (the standard regimen is a combination of the following drugs for 6 months): Adults – rifampicin: 600 mg once a month; LEPROSY – dapsone: 100 mg once a day. Children should receive appropriately scaled-down doses (in child blister- packs). I A core element of the elimination strategy is to make diagnosis and MDT available at all health centres, to all existing leprosy patients. MDT is provided free of charge by WHO. Any interruption of treatment schedules has serious implications for treatment outcome. II

Prevention and control The following actions are essential for prevention of leprosy and maintaining the ongoing elimination campaign: III

ensuring that accessible and uninterrupted MDT services are available to all patients through flexible and patient-friendly drug delivery systems; guaranteeing that MDT services are sustainable by integrating leprosy serv- IV ices into the general health services and building the ability of general health workers to treat leprosy;

Communicable disease epidemiological profile 102 CENTRAL AFRICAN REPUBLIC AND CHAD are created. created. are facility health at any treatment and for diagnosis to come notforward hesitate will patients which in environments that It important is to stigmatization. lead can and of dubious is value patients leprosy known with contact Reducing levels. local and national global, the at changed be to has of leprosy image The treatment. early and self-reporting to an obstacle remains disease the with associated stigma age-old The Communicable disease epidemiological profile epidemiological disease Communicable leprosy. against specifically not undertaken be need therefore and TB against method control of the part is this disease; the against protection may induce vaccination BCG Immunization

made towards elimination through national disease surveillance systems. systems. surveillance disease national through elimination towards made progress and ofcare patient quality services, of MDT performance monitoring of leprosy; image the changing and awareness community by promoting treatment early and self-reporting encouraging 103 LYMPHATIC FILARIASIS

Country-specific disease burden Lymphatic filariasis (LF) is endemic in both Central African Republic and Chad.

Description Infectious agent Helminth: Wuchereria bancrofti, a filarial worm belonging to the class Nematoda.

Case definition Clinical case definition Hydrocele or lymphoedema in a resident of an endemic area for which other causes of these findings have been excluded.

Laboratory criteria Positive parasite identification by: LYMPHATIC FILARIASIS LYMPHATIC

direct blood examination; or ultrasound; or positive antigen detection test. I

Case classification Suspected: not applicable. Probable: a case that meets the clinical case definition. II Confirmed: a person with positive laboratory tests even if he/she does not meet the clinical case definition.

The burden of lymphatic filariasis, as measured in disability-adjusted life years III (DALYs), is the highest of all tropical diseases after malaria.

Mode of transmission The bite of infected blood-feeding female mosquitoes (mainly Anopheles spp., also IV Culex spp.) that transmit immature larval forms of the parasitic worms from human to human.

Communicable disease epidemiological profile 104 CENTRAL AFRICAN REPUBLIC AND CHAD attacks also increases during the wet season. wetseason. the during increases also attacks (ADL) adenolymphangitis acute of frequency The April–September). equator: of the (north of transmission risk ahigher with associated to be likely is season rainy the Communicability period Communicability Incubation period Communicable disease epidemiological profile epidemiological disease Communicable Overcrowding. versa. or vice areas endemic into displaced may be populations Disease-free movement. Population Risk factors for increased burden is not outbreak-prone. disease The Recent epidemics Seasonalit district. same the within another and one village between even and to another, area one geographical from greatly However, vary rates zones. prevalence tiguous con in distributed is LF endemic, Where Region. African WHO of the countries LF-endemic the in to be estimated is at-risk population global (382 of the million) some30% antigenaemia. date, To or >1% is where prevalence microfilaraemia endemic as categorized are Countries countries. endemic both are CAR and Chad distribution Geographical Epidemiology bite).infective the 5–10 after years 6–12 blood to (from months peripheral the in are present microfilariae longAs as

and chyluria (cloudy/milky urine). (cloudy/milky chyluria and females in breasts enlarged scrotum), of the of limbs), (swelling hydrocele ing (swell elephantiasis may include illness of chronic manifestations years: 5–20 vomiting). and nausea fever, by accompanied often and ducts, nodes lymph of inflammation and signswith of lymphatic damage. Repeated attacks of “filarial fever” occur (pain in blood prepatentperiod) (the to appear microfilariae 6–12 for months the y. y. Even if data on the seasonality of vectoral density are not available, not available, are density of vectoral seasonality on the data Even if Living in crowded conditions increases the risk of transmission. of transmission. risk the increases crowded conditions in Living - - 105

Poor access to health services. Lack of early diagnosis and treatment as a result of difficulties in diagnostic methodology and accessing health services (geographical, financial, security) increases the risk of transmission. Lack of safe water and poor sanitation. Hygienic measures for the affected body parts are essential to prevent ADL attacks secondary to lymphoedema. Poor sanitation may contribute to creating breeding sites for mosquito vectors (especially Culex spp.).

Other factors Economic and social impact: filariasis is closely associated with the economies and infrastructure of endemic communities. There is an established link between the prevalence of LF, reduced productivity and poverty. LF exerts a heavy social burden that is especially severe because of the specific attributes of the disease, particularly since chronic complications are often hidden and considered shameful. For men, genital damage is a severe handicap, leading to physical limitations and social stigmatization. For women, shame and taboos are also associated with the disease. The introduction of a Programme to Eliminate Lymphatic Filariasis (PELF) in the countries brings “beyond filariasis” benefits, since albendazole is also an effective and safe drug for treating soil-transmitted helminths; ivermectin is effective against many intestinal parasites, scabies and lice. FILARIASIS LYMPHATIC Health programmes coupled with development projects addressing the key components that contribute to LF can improve the chances of success. Specifically, projects that would reduce mosquito breeding sites, improve housing and sanita- I tion facilities, and stimulate economic development should be considered. Additionally, because of the industry-wide impact of LF in some regions, there is great potential for a strong private-sector role in the elimination of this disease as a public health problem. II However, owing to financial constraints and inadequate staffing, less than 10% of the at-risk population are covered by mass drug administration (MDA) so far. In addition, the implementation of other programme components, such as vector control and disability management and prevention, are consequently delayed. III

Prevention and control measures Case management IV Hygiene measures for the affected body parts (and, when necessary, antibiotics and antifungal agents) can reduce the risk of ADL:

Communicable disease epidemiological profile 106 CENTRAL AFRICAN REPUBLIC AND CHAD burden may cause encephalopathy. may cause burden loa Loa high with individuals in and reaction allergic an cause maythat of microfilariae destruction loa from Loa However, suffering for treatment. LF those therapy dual as albendazole with used often is ivermectin as important is Suchmapping distribution. loa Loa and of LF mapping the require that interventions on community based is Control patients: microfilarial-positive for individual regimen Drug Communicable disease epidemiological profile epidemiological disease Communicable 34 been completed in CAR or Chad. CAR completedin been loa Loa and of LF distribution geographical of the aware to be

coinfection should not be exposed to ivermectin as it promotes as amassive to ivermectin not exposed be should coinfection usage has not been attempted and is not recommended to be given alone. alone. given to be not is recommended and attempted not been has usage of its for W. but optimization bancrofti, macrofilaricidal be can Albendazole completely. infection cure not thus does and (i.e. not it is macrofilaricidal) worms adult kill not to appears microfilaraemia, decreasing in effective very although Ivermectin, used. may be albendazole and ivermectin Alternatively, DEC. with treated before being parasites these with for coinfection examined be infections other these for endemic areas in live who filariasis Bancroftian with patients loa Loa worm nematode by the caused (disease or loasis onchocerciasis either with patients of DEC in use the Since microfilaria. of the number in reducing and worm theadult killing in effective equally is dose However, 6mg/kg necessary. asingle if at intervals 1–6 month repeated for dose 12 days, single (DEC) 6mg/kg citrate Diethylcarbamazine necessary. may be antibiotics systemic cases, severe in abrasions; or wounds small to treat creams or antifungal antibiotic antiseptic, use footwear; comfortable wear clean; and short nails keep to promote flow; lymph exercise night; at limb affected the raise dry; part affected the water, andkeep clean and soap with daily twice parts affected the wash who.int/publications/2006/9241547103_eng.pdf). (http://whqlibdoc. helminthiasis human in chemotherapy preventive on Guidelines WHO to refer Please ) may be unsafe, it is important that that important it is unsafe, ) may be 34 It is therefore important It important therefore is . Mapping has not has . Mapping

107

Prevention and control Prevention of infection may be achieved only by either reducing contact between humans and vectors or reducing the amount of infection the vector can acquire, by treating the human host.

Population level Mass chemotherapy with safe drugs given once a year to the entire population at risk is a safe and feasible approach to reducing transmission. This may be implemented by community volunteers. The recent advent of the extremely effective single-dose, once-yearly drug regimen has permitted an alternative approach and the launch of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) in 2000. GPELF has two main goals:

to interrupt transmission of infection; and to prevent disability caused by the disease.

In order to interrupt transmission, the entire at-risk population must be treated for a period long enough to ensure that levels of microfilariae in the blood remain below those necessary to sustain transmission. Therefore, a yearly 1-dose MDA of LYMPHATIC FILARIASIS LYMPHATIC the following drugs must be given:

As CAR and Chad are also coendemic with concurrent onchocerciasis, the recommended drugs are: albendazole 400 mg + ivermectin 150 µg/kg body I weight, once a year for at least 5 years or until the microfilaraemia prevalence is brought below 1% in most areas and less than 1 in 1000 school entry children show infection, whichever occurs later. In areas with concurrent loasis: mass interventions cannot be envisaged sys- II tematically because of the risk of severe adverse reactions in patients with high-density Loa loa infections (about 1 in 10 000 treatments). Currently, MDA with ivermectin cannot be implemented in areas coendemic for Loa loa.

To alleviate and prevent suffering and disability: III

increase lymph flow through elevation and exercise of the swollen limb; reduce secondary bacterial and fungal infections of limbs or genitals where the lymphatic function has already been compromised by filarial infection. IV Secondary infection is the primary determinant of the worsening of lymphoedema and elephantiasis.

Communicable disease epidemiological profile 108 CENTRAL AFRICAN REPUBLIC AND CHAD Individual level Individual of LF.mission trans in reducing have abenefit also will control, for malaria encouraged already (LLINs), nets insecticidal of use long-lasting large-scale The some situations. in trol con vector additional through more rapidly achieved be of could GPELF goal the transmission, LF or to reduce interrupt expected be MDA may generally Whereas able footwear. of comfort wearing and limbs, of the exercising water, daily clean and soap with washing of regular consist Measures of lymphangitis. episodes damaging and tating debili painful, in preventing effective very are care local and hygiene Scrupulous Communicable disease epidemiological profile epidemiological disease Communicable unlikely. are LF of outbreaks incubation, long and low infectivity relatively of Because Epidemiccontrol materials. impregnated or insecticide- LLINs of repellents, use the through decreased may be mosquitoes infected with Contacts dawn. and of dusk hours the bite between usually vectors LF - - - - 109 MALARIA

Country-specific disease burden In both CAR and Chad, malaria risk exists throughout the country. Both countries face major challenges with regard to malaria control.

Central African Republic Few data are available, but WHO has estimated the total number of malaria cases at 1 600000. A Malaria Strategic Plan was introduced in 2007.35

Chad In Chad, malaria is one of the most important public health problems. At health- facility level it represents 30% of consultations and 15% of reported deaths. It is the major cause of morbidity and mortality especially in pregnant women and children < 5 years. The 410 649 malaria cases reported in 2005 may represent a considerable underestimation of the true burden of disease.

WHO-estimated burden of malaria MALARIA

Estimated cases

Age group Numbers Lower range Upper range

Fever suspected of All ages 7 095 000 3 965 000 10 400 000 I being malaria < 5 years 4 301 000 760 000 8 250 000

Malaria cases All ages 4 179 000 2 335 000 6126 000 < 5 years 2 533 000 447 000 4 859 000

Malaria deaths All ages 18 000 8 900 30 000 II < 5 years 17 000 8 300 28 000

Malaria case-fatality All ages 0.43 rate (%) < 5 years 0.67

Source: World Malaria Report 2008. Geneva, World Health Organization, 2008. III

The three climatic divisions of the country (northern desert, central Sahelian transition zone and southern tropical) determine the epidemiological profiles of malaria. Most of the cases occur in the hyperendemic southern tropical part of IV

35 Source: World Malaria Report 2008. Geneva, World Health Organization, 2008.

Communicable disease epidemiological profile 110 CENTRAL AFRICAN REPUBLIC AND CHAD (IMCI) algorithms for diagnosis and treatment. and for diagnosis algorithms (IMCI) Illnesses of Childhood Management by Integrated aided may be which toring moni close and suspicion clinical index of high a requires comorbidity of risk The infection. malarial the outcome from to lethal vulnerable most is group, which age this in risk malaria high and infection of prevalence high the given tified jus is alone diagnosis on clinical based Treatment for malaria malaria. as treated be <5years children in fever cases all that recommended it is Chad, and CAR as such settings, high-transmission stable with countries African sub-Saharan In Description 2008–2012. period to cover the of validation, process the in is which Plan, Strategic Malaria the National revised recently has of Health Ministry The of epidemics. at risk is and period, transmission short and rainfall in variation seasonal the given of disease inconsistent burden an zone experiences population)the (29% of transition The (1% low- and of no- endemicity area an population). is of the north desert dry the whereas population, 70% of the houses which CAR) (bordering country the Communicable disease epidemiological profile epidemiological disease Communicable definition Case deaths. malaria of all over 90% causes ease, falciparum Plasmodium Infectious agent

by microscopy or rapid diagnostic tests (RDT) detecting antigen. antigen. detecting (RDT) tests or rapid diagnostic by microscopy infection malaria of diagnosis of confirmation laboratory with malaria severe Probable case Probable Confirmed case ( case Confirmed

respiratory distress, pulmonary oedema and shock). and oedema pulmonary distress, respiratory acute bleeding, spontaneous haemoglobinuria, jaundice, anaemia, severe convulsions, of consciousness, loss (e.g. disorientation, failure to organ related symptoms and signs associated and weakness extreme with ness malaria Severe and diarrhoea, headache, back pain, chills, muscle pains and fatigue). and pains muscle chills, pain, back headache, diarrhoea, and vomiting nausea, as such symptoms other or without (with hours 48 past malaria Uncomplicated uncomplicated or severe or uncomplicated : patient with fever or a recent history of fever, plus fever ordrowsi arecent history with : patient , which causes the most life-threatening form of the dis of form the life-threatening most the causes , which : patient with fever or history of fever within the the of fever within fever or history with : patient ): patient with uncomplicated or uncomplicated ): with patient

- - - - 111

Mode of transmission Vector-borne, through the bite of certain species of Anopheles mosquitoes that bite mainly between dusk and dawn. Malaria may also be transmitted through transfusion by injection of infected blood. Rarely, infants may contract malaria in utero (through transplacental transfer of parasites) or during delivery. Transmission is related to the presence of infective female Anopheles mosquitoes and of infective gametocytes in the blood of patients. Untreated or insufficiently treated patients may be a source of mosquito infection for up to 40 years in P. malariae malaria and 5 years in P. vivax and P. ovale malaria.

Significant biological features of some major malaria vectors in Africa

Anopheles Resting Feeding time Host Breeding sites Insecticide species location and location preferences susceptibility

A. gambiae Mainly indoors Mainly late Mainly humans Sunlit temporary Resistance to pools, rice fields DDT, HCH,a Indoors recently to pyrethroids in west Africa MALARIA

A. arabiensis Indoors and Mainly late Humans and Temporary Resistance to outdoors animals pools, rice fields DDT, and to Indoors and malathion in outdoors I Sudan

A. funestus Mainly indoors Mainly late Mainly humans Semi-permanent Resistance to and permanent DDT, recently to Indoors water, especially pyrethroids in with vegetation, southern Africa. II swamps, slow streams, ditch edges

Source: Malaria control in complex emergencies. An inter-agency field handbook. Geneva, World Health III Organization, 2005 (www.who.int/malaria/interagencyfieldhandbook.html). a Hexachlorocyclohexane

Incubation period IV Average incubation periods for mosquito-transmitted P. falciparum is 9–14 days, P. vivax and P. ovale 12–18 days and P. malariae 18–40 days.

Communicable disease epidemiological profile 112 CENTRAL AFRICAN REPUBLIC AND CHAD Epidemiology season. rainy the of period the after just and during occurs transmission highest The vegetation. and distribution water surface perature, tem humidity, rainfall, altitude, include: transmission influence which Factors period Communicability exposure. possible last the after cases) (ormonths rare in later even two and risk malaria to exposure possible first the one after week between time at any starts fever that of unexplained cases all in considered be should Malaria Communicable disease epidemiological profile epidemiological disease Communicable Seasonality Eritrea. and Sudan Niger, Chad, Nigeria, Faso, Burkina Mali, Mauritania, Senegal, through running and ofHorn Africa to the coast Atlantic the from extending south, to the regions more fertile and the north to Sahara the zonebetween boundary the is Africa in zone Sahelian The compromised. is survival mosquito above and often 32 °C are temperatures areas, anddesert semi-arid In significantly. transmission opment malaria and devel parasite decreases below 18 which °C, may fall temperatures m, above 2000 highlands In transmission. parasite for development malaria complete vector and conditions climatic 18–32 suitable considered range are °C the Temperatures within distribution Geographical itself. the conflict by caused those exceed often deaths malaria These emergencies. and violence of war, local wake the in occur Africa in deaths of malarial 30% healers. or traditional pharmacies go to private they as services byhealth public tured nor cap systems information health national to the not reported are cases many since cases, of malaria number total actual the underrepresent cases reported tries, coun most In globally. deaths and cases of malaria burden highest the has Africa General

the rainy season. rainy the after just and May to December, during from expected is season transmission peak The country. the throughout year-round exists risk transmission Chad: whole country. the in year the throughout –occurs P. falciparum by caused –predominantly transmission malaria Republic: African Central - - - - 113

Alert threshold Any increase in the number of cases above what is expected for that time of the year in a defined area. For emergencies and for settings where no historical data are available for comparison, a “clustering of severe cases and deaths” should raise an alarm. Another method suggested for defining a threshold is a doubling of cases compared with the baseline (average weekly number of cases compared to the weekly average over the previous 2–3 weeks), adjusted for fluctuations in clinic attendance resulting from external factors – such as a sudden influx of a migrant population. Other features of epidemic malaria are an increase in the incidence of severe cases and an increase in the incidence in children > 5 years and adults.

Risk factors for increased burden Population movement. The potential for epidemics may increase because of the influx of less-immune populations moving from areas of no or low malaria transmission to highly endemic areas. The movement of populations from, into and within the region is likely to affect the malaria situation. Displaced people MALARIA move between regions of a range of endemicities. Although malaria transmission occurs throughout the year in most of the subregion, not all of the population have protective levels of acquired immunity. I Overcrowding. As a result of increased population density, exposure to mosquito bites in temporary shelters increases.

Poor access to health services. Delay in access to effective treatment increases the likelihood of severe disease and death. This delay also increases the pool of II malaria gametocyte carriers (the mature sexual stage of the parasite in humans that, once picked up in the blood-meal of a mosquito, develops into the infective stage for transmission to another human).

Food shortages. Malnutrition increases vulnerability to severe malaria once III infection has occurred. Severe malnutrition often masks symptoms and signs of infectious diseases, making prompt clinical diagnosis and early treatment very difficult. This may result in increased mortality. IV Lack of safe water and poor sanitation. Temporary stagnant water bodies may increase malaria-vector breeding opportunities, especially in arid environments.

Communicable disease epidemiological profile 114 CENTRAL AFRICAN REPUBLIC AND CHAD 36 National malaria treatment protocol, Chad protocol, treatment malaria National (http://apps.who.int/malaria/amdp/amdp_afro.htm) 2008 May –AFRO, database AMDP Global Programme, Malaria Global WHO Source: Source: Republic African Central protocol, treatment malaria National Prevention and control measures Communicable disease epidemiological profile epidemiological disease Communicable before purchase. manufacturer the from requested be should data heat-stability that It recommended is at stored <30°C. be should usually and conditions humid hot and in stored when sensitivity RDTs their may lose patients. treated or for rescreening clearance parasite to assess used on not microscopy. therefore be RDTs should parasites longer have detectable no when patients even infection, malaria ofa treatment effective 14 after days for up to results test to produce positive may continue (HRP-II) protein-II rich histidine- detect RDTs that (RDTs) tests some clinics. in doneis by rapid diagnostic diagnosis Malaria laboratories. private and facilities health district other hospitals, district and at regional available are (microscopy) services diagnostic Laboratory * pregnancy. during treatment preventive IPTp =intermittent pyrimethamine; =sulfadoxine- SP =quinine, QN =artemether-lumefantrine, AL AQ =amodiaquine, =artesunate, AS (http://apps.who.int/malaria/amdp/amdp_afro.htm) 2008 May –AFRO, database AMDP Global Programme, Malaria Global WHO Source: P. falciparum P. falciparum Species Species

wpro.who.int/sites/rdt. http://www. and http://www.who.int/malaria/rdt.html to: refer please RDTs, on information more For Policy adopted, not currently being deployed, implementation process ongoing process implementation deployed, being currently not adopted, Policy or AL*or AS+AQ* Unconfirmed AL* Unconfirmed Uncomplicated Uncomplicated or AL*or AS+AQ* confirmed Laboratory- AL* confirmed Laboratory- QN (7 days) (7 QN QN (7days)QN failure Treatment failure Treatment QN (7 days) (7 QN QN (7days)QN malaria malaria Severe malaria Severe QN QN (7days)QN Treatment Treatment 36

Pregnancy Pregnancy

SP (IPTp)SP SP (IPTp)SP Prevention Prevention

115

Key strategies for malaria control include:

capacity-building of the national malaria control programme in management and coordination; case management; vector control; epidemic preparedness and response in epidemic-prone districts; information, education and communication materials for malaria control and community mobilization; community-based malaria control; operational research; strengthening of monitoring and evaluation.

Both countries have a five-year strategic plan for malaria control (CAR, 2007–2011; Chad, 2008–2012). Intermittent preventive treatment (IPTp) with sulfadoxine- pyrimethamine at least twice during pregnancy (during the second and third trimesters) is recommended for pregnant women living in areas where transmission is high and where SP is > 80% effective. It is best implemented through antenatal care. Long-lasting insecticidal nets (LLINs) provide personal protection for all those who MALARIA sleep under the net. They also have the potential to significantly reduce the adult mosquito population when coverage is above 80% (community impact), thereby reducing transmission and subsequently morbidity and mortality. LLINs may be distributed with integrated mass vaccination campaigns or as stand-alone distributions. I Health education on proper use and care is vital for the success of LLIN programmes. Periodic indoor spraying of shelters with residual insecticide (IRS) may reduce transmission when applied according to WHO recommendations and when the following conditions are met: II a high percentage of the structures in an operational area have adequate sprayable surfaces, and can be expected to be well sprayed; the majority of the vector population is endophilic, i.e. rests indoors; the vector is susceptible to the insecticide in use. III

The main purpose of IRS is to reduce transmission by reducing the survival of malaria vectors entering houses or sleeping units. IRS is not applicable during acute phases 37 of emergencies. It may be useful in well-organized temporary settlements/camps. IV

37 http://www.who.int/malaria/indoorresidualspraying.html.

Communicable disease epidemiological profile 116 CENTRAL AFRICAN REPUBLIC AND CHAD and Chad are: atovaquone-proguanil, doxycycline or mefloquine. doxycycline atovaquone-proguanil, are: Chad and CAR to travellers international for options chemoprophylaxis The recommended country. the entering or aweek more after fever for occurring any treatment and diagnosis seek immediately and dawn, and dusk to prevent bites between mosquito protection personal use and chemoprophylaxis use should travellers International acceptability. (IRS) spraying residual indoor improving and use LLIN for effective for fever cases, behaviour treatment-seeking to improve rapid important is level at community education Vigorous health breeding sites: breeding of vector the limited. number To reduce often is impact and scale, on alocal except an emergency of acutephase the during difficult may control be Environmental Communicable disease epidemiological profile epidemiological disease Communicable 38

ing and/or foring animals). for wash used are ponds if may not acceptable be this (although ponds drain drains; rainwater and water-tap stands around water clean drain expert advice); expert (seek number in limited are these if sites breeding vector in larvicides use More information for international travellers is available at http://www.who.int/ith. at available is travellers international for information More 38

- 117 MEASLES

Country-specific disease burden Central African Republic Reported cases, Central African Republic, by year

Year 2007 2006 2005 2004 2003 2002 2001 2000

49 3 471 2 013 652 938 2 837 3 207

Source: Data provided by the Ministry of Health through the WHO/UNICEF joint reporting form (http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencemea.htm).

Outbreaks:

December 2007 – January 2008: 116 cases; 1 death; CFR 0.9%; Ouham. January–June 2005: 195 cases; 18 deaths; CFR 9.2%; Lobaye. December–May 2004: 225 cases; 36 deaths; CFR 16%; Nana-Mambère.

January–June 2004: 1040 cases; 80 deaths; CFR 13%; Basse-Kotto. MEASLES January–May 2003: 443 cases; 86 deaths; CFR 19.4%; Ouham. January–April 2002: 287 cases; 19 deaths; CFR 6.6%; Kemo. January–June 2002: 495 cases; 11 deaths; CFR 2.2%; Nana-Mambère. I

Differences between reported measles cases in the WHO/UNICEF joint reporting form (JRF) and the outbreak data above are probably due to underreporting of cases in the JRF. In the joint global plan for reducing measles mortality, 2006– II 2010, WHO and UNICEF have identified 47 priority countries to be targeted. These countries account for more than 95% of global measles deaths and include CAR.

Measles morbidity and mortality has decreased over the past few years. This is attributable to increasing routine measles vaccine (MV) coverage as well as the III implementation of a nationwide catch-up vaccination campaign (2005–2006).

Because of human and cold-chain resource constraints, the nationwide catch-up campaign was conducted in two phases, October 2005 and January 2006, target- IV ing 1 838 877 children aged 6 months to 14 years. Overall campaign coverage was 92% and administrative coverage results are shown in the map below.

Communicable disease epidemiological profile 118 CENTRAL AFRICAN REPUBLIC AND CHAD

Communicable disease epidemiological profile epidemiological disease Communicable Measles vaccine coverage in the campaign targeting children aged 6 months to 14 years, by prefecture, Central African Republic, 2005–2006 119

In 2006, CAR also initiated national child survival days (journées nationales de survie de l’enfant) as an additional strategy to improve routine vaccination coverage. Three rounds were conducted in 2006, in August, September and October. The result of these activities was that only 3 laboratory-confirmed cases of measles were detected in 2006 and no outbreaks reported. The outbreak in Ouham province (2007– 2008) is the first reported and confirmed outbreak since the catch-up campaign. The presence of the Pasteur Institute in Bangui Institut( Pasteur de Bangui) and its close collaboration with the Ministry of Health and WHO, have greatly facilitated the implementation of measles (and yellow fever) case-based surveillance. Case-based measles surveillance performance is among the best in the central African subregion. The non-measles febrile and rash investigation rate was 5.6 per 100 000 population and 22 of 24 districts (sous-prefectures) investigated at least one suspected measles case with a blood specimen in 2007. A nationwide follow-up campaign is planned for October or November 2008. This campaign will target children aged 6–59 months and will integrate the distribution of treated bednets, deworming and vitamin A supplementation. Providing an additional dose of oral polio vaccine (OPV) is also under discussion.

Chad MEASLES Reported cases, Chad, by year

Year 2007 2006 2005 2004 2003 2002 2001 2000 441 1 594 2 10 324 15 801 7 277 27 908 3 546 I

Source: Data provided by the Ministry of Health through the WHO/UNICEF joint reporting form and WHO regional offices (http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencemea.htm).

Outbreaks: II February–June 2007: 147 cases; 1 death; CFR 0.7%; Ndjamena. January–May 2005: 20 278 cases; 516 deaths; CFR 2.5%. Province, cases, deaths. Batha, 750, 31; Chari Baguima, 8 039, 164; Kanem, III 516, 2; Lac, 225, 2; Logone occidental, 375, 5; Logone oriental, 725, 33; Mayo-Kebi, 1 008, 24; Moyen Chari, 5 589, 169; Quaddai, 1 050, 11; Salamat, 1 460, 34; Tandjile, 280, 5. Differences between reported measles cases in the WHO/UNICEF joint reporting IV form (JRF) and the outbreak data above are probably due to underreporting of cases in the JRF.

Communicable disease epidemiological profile 120 CENTRAL AFRICAN REPUBLIC AND CHAD Catch-up measles vaccine coverage by region, Chad, 2005–2006 Chad, by coverage region, vaccine measles Catch-up campaign catch-up vaccination nationwide the since decreased dramatically has cases Response). of and reported The number Surveillance Disease Integrated of Health, 1% 5% between and (Ministry varied ratios Case-fatality annually. ed were report of average over cases 14 an 000 2004, and 1990 between 2006), in ed (23% coverage report immunization measles low routine of persistently Because Communicable disease epidemiological profile epidemiological disease Communicable - - 121 conducted between March 2005 and January 2006. Overall, 5 060 371 children aged 9 months to 14 years were targeted for MV during three campaign rounds. During these rounds, national vaccination administrative coverage was reported as being 92% with variation at the provincial and district levels.

Administrative vaccination coverage, catch-up supplemental immunization activity (SIA)

Campaign Dates Target No. districts reporting Coverage phase population administrative coverage (n = 54)

< 90% 90–94% ≥ 95%

Phase 1 14–24 March 303 062 – 2 2 97% 2005

Phase 2 26 Sept–5 Oct 2 045 298 7 5 6 80% 2005

Phase 3 16–25 January 2 712 011 – 1 31 101%* 2006

* Total population was underestimated

Despite high administrative vaccination coverage levels attained by the majority MEASLES of districts, laboratory-confirmed cases were detected in several districts in the months following the campaign and an outbreak occurred in Ndjamena approximately 14 months after the catch-up supplemental immunization activity (SIA) I (albeit with far fewer cases and deaths than during the 2005 outbreak). The sub-optimal quality of the catch-up SIA and continued poor routine vaccination coverage (~20%) results in an ever-growing susceptible population. A follow- up campaign in Chad is tentatively scheduled to occur in the last quarter of 2008 II following the rainy season and should target approximately 1.6 million children aged 6–59 months. Unfortunately, politicomilitary events as well as the spread of a current polio epidemic may defer this campaign. Measles case-based surveillance with laboratory-confirmation of suspected cases III was initiated subregionally in 2006. Prior to this, laboratory confirmation of suspected measles outbreaks was undertaken at the national reference laboratory on an ad hoc basis starting in 2004. Although cascade training for measles and yellow fever case-based surveillance of regional and district surveillance focal points IV was completed in May 2007, case-based measles surveillance performance continues to be poor. The non-measles febrile and rash investigation rate of 0.80 per

Communicable disease epidemiological profile 122 CENTRAL AFRICAN REPUBLIC AND CHAD malnutrition, encephalitis, otitis media, croup, subacute sclerosing panencephalitis). sclerosing croup, subacute media, otitis encephalitis, malnutrition, stomatitis, diarrhoea, (pneumonia, complications of medical or absence presence by the uncomplicated as (simple) complicated or classified further clinically may be Cases Clinical case definition case Clinical definition Case Morbillivirus (genus virus Measles Infectious agent Description specimen. ablood with case one suspected at least investigated of districts 50% only and population, 100 per 000 of ≥ 2.0 objective below the well is population 100 000 Communicable disease epidemiological profile epidemiological disease Communicable person. infected an with contact close (e.g. in object been toys) an has or people via that of infected secretions throat and nasal the with contact or direct spread; by droplet Airborne Mode of transmission classification Case antibodies. IgM of measles-specific Presence criteria Laboratory

been laboratory-confirmed during the previous 30 days. days. 30 the previous during laboratory-confirmed been has an outbreak zonewhere or district same the from is and definition case clinical the that meets case a linkage: epidemiological through Confirmed laboratory-confirmed; is and definition case clinical the that meets case a Laboratory-confirmed: infection. measles worker suspects health a clinical whomin anyperson or definition case clinical the meets that acase Suspect: infection. measles worker suspects health whom aclinical in person or any with: person Any

cough or coryza (i.e. runny nose) or conjunctivitis (i.e. eyes); red nose) (i.e. or conjunctivitis runny or coryza cough maculopapular (i.e. non vesicular) rash; and and (i.e. rash; non vesicular) maculopapular and fever; , family Paramyxoviridae, family ). 123

Incubation period After infection, there is an asymptomatic incubation period of 10–12 days, with a range from 7 to 18 days from exposure to the onset of fever.

Communicability period Measles is most infectious from 4 days before the rash until 1–2 days after rash onset.

Epidemiology General In 2005, the World Health Assembly adopted an ambitious global goal for measles control, as part of the Global Immunization Vision and Strategy document, that aims to achieve a 90% reduction in measles mortality by 2010 compared with 2000. Measles is one of the most contagious diseases known and remains a leading cause of death among children worldwide. Most children will have uncomplicated measles and require supportive care as outpatients. The overwhelming number of measles deaths occur in countries with a low GNP, weak health infrastructure, or experiencing or recovering from war, civil strife or natural disaster. Infection rates soar because of the deterioration of routine immunization and increased transmission MEASLES among refugees and IDPs as a result of crowded living conditions.

Geographical distribution I Measles is still widely distributed and reported from various parts of Chad and CAR.

Seasonality The highest incidence of cases is usually observed between the end of the dry season and the beginning of the rainy season (north of the equator: February–March). II

Alert threshold One case must lead to an alert. Laboratory-confirmation of all cases is not required; only a few cases from each outbreak need to be laboratory-confirmed. III

Risk factors for increased burden Population movement. Influx of non-immune populations into areas where the IV pathogen is circulating or of infected individuals into areas where the population is not immunized.

Communicable disease epidemiological profile 124 CENTRAL AFRICAN REPUBLIC AND CHAD Prevention and control measures Adeficiency. vitamin worsen and malnutrition protein–energy acute trigger may disease The of measles. attack an following death and complications ofrisk high are particularly at children Adeficiency.Malnourished vitamin and malnutrition with children more among is severe Disease shortages. Food Asupplements. of vitamin administration the including management, case by effective reduced may be ratios Case-fatality services. health to access Poor transmission. Overcrowding. Communicable disease epidemiological profile epidemiological disease Communicable Outbreak response ensured. be should sharps of used disposal Safe recommended. are boxes safety and syringes autodisable immunization, during To safety injection ensure guidelines. WHO per as initiated be should A vitamin with treatment groups, age in older deficiency A vitamin of clinical evidence is there If disease. of the complications the minimizes it as <5 years, aged those all in vaccination measles with necessary is mentation Asupple Vitamin to 15 6months years. aged those targeting vaccination with preventable are populations malnourished in mortality and morbidity Measles doses. between 1month of at least interval an with of age, 9months ing reach after possible as soon as given be should This vaccination. measles second a receive should of age <9months measles against vaccinated are who Children to 5years. or 6months to 12 years 6months e.g. limited, are resources if reduced maybe range age group. age The the among susceptibility of high on evidence based be should and of lower is groups to older age priority Expansion history. or disease status of vaccination regardless to 15 6months years, aged children nize immu is to The priority or unknown. <80–90% is coverage vaccination if possible as soon as immunized be should at risk emergency, population acute the an In Immunization in emergency and post-emergency phases response. outbreak measles and immunization; campaigns/routine vaccination mass prevention through measles major components: have two settings emergency in measures control Measles

Inform the health authorities if one or more suspected cases are identified. are cases one or more if suspected authorities health the Inform Crowded conditions and poor indoor ventilation facilitate rapid facilitate ventilation indoor poor and Crowded conditions - - - 125

Confirm the suspected outbreak, following WHO guidelines. Investigate suspected case: check whether case fulfils the case definition, record date of onset, age and vaccination status. Confirm the diagnosis: collect blood specimens from 3–5 initial reported cases. Assess the extent of the outbreak and the population at risk. Implement outbreak response measures as follows: Give priority to proper case management and immunization of groups at highest risk (e.g. children aged 6 months – 15 years) as soon as possible even in areas not yet affected where the outbreak is likely to spread. This range may be reduced if resources are limited, e.g. 6 months to 12 years or 6 months to 5 years. Through social mobilization ensure parents bring previously unvaccinated children for immunization. The presence of several cases of measles in an emergency setting is an indication for a measles immunization campaign. Even among individuals who have already been exposed, and are incubating the natural virus, measles vaccine, if given within 3 days of exposure, may provide protection or

modify the clinical severity of the illness. MEASLES Isolation is not indicated and children should not be withdrawn from feed ing programmes.

Case management I For uncomplicated cases:

Give vitamin A immediately upon diagnosis and ensure that the child receives a second dose the next day (may be given to parent to administer at home). II Advise the parent to treat the child at home (control fever and provide nutritional feeding).

For cases with non-severe eye, mouth or ear complications: III

Children may be treated at home. Give vitamin A immediately upon diagnosis and ensure that the child receives a second dose the next day (may be given to parent to administer at home). IV If pus is draining from the eyes, clean eyes and treat with 1% tetracycline eye ointment.

Communicable disease epidemiological profile 126 CENTRAL AFRICAN REPUBLIC AND CHAD Dosages of vitamin A in measles-treatment regimens measles-treatment Ain vitamin of Dosages pneumonia): ulcers, mouth or extensive deep cornea, of clouding signs, danger (any general measles complicated severe, with For cases Communicable disease epidemiological profile epidemiological disease Communicable Note Children >11 months Children 6–11 months Infants Infants <6months Infants Age

Vitamin A should not be given to women pregnant. may who not given be be Ashould Vitamin or unconsciousness. lethargy convulsions, vomiting, repeated or breastfeed, to drink inability signs: danger General later. weeks 2–4 dose third and day next the dose asecond Aimmediately, vitamin receive he or sheshould then ulceration), or corneal clouding corneal dryness, corneal and conjunctival Bitôt spots, ness, blind night (i.e. Adeficiency vitamin indicating signs eye any has child the If ointment. eye apply 1% tetracycline and eyes clean eye, the from ordraining pus cornea of the clouding is there If appropriate antibiotic. an Treat with pneumonia to hospital. Refer urgently diet. quality high- and fluids sufficient with present, if diarrhoea, and Treat malnutrition development. under currently guidelines IMCI and policy ARI national second-line), – per as co-trimoxazole or –first-line, (amoxicillin for 5days antibiotics with treat and discharge ear ear, clean the from draining is pus If violet. gentian with treat ulcers, mouth are there If Immediately on diagnosis on Immediately 200 000 IU 000 200 100 000 IU 000 100 50 000 IU 000 50 Following day Following 200 000 IU 000 200 100 000 IU 000 100 50 000 IU 000 50 - 127 MENINGOCOCCAL DISEASE (MENINGITIS AND MENINGOCOCCAL SEPTICAEMIA)

Country-specific disease burden Central African Republic Outbreaks:

November 2007 – February 2008: 45 cases; 5 deaths; CFR 11.1%; NmA, Kaga- Bandoro, Nana-Grèbizi). April 2004: 43 cases; 7 deaths; CFR 16.27%; NmA, Nana Bougila, Zere, Ouham. February–June 2001: 1816 cases; 343 deaths; CFR 18.8%; Paoua, Ouham-Pendè in the north-western part of the country bordering on Chad and Cameroon (including 3 Haj pilgrims N. meningitidis serogroup W135). February 2000: 86 cases; 14 deaths; CFR 16.2%; Bamingui-Bangoran, Haute Kotto, Ouham-Pendè and Vakaga).

Chad MENINGOCOCCAL SEPTICAEMIA) AND MENINGOCOCCAL DISEASE (MENINGITIS Outbreaks:

March–April 2007: 350 cases; 17 deaths; CFR 5.1%; predominantly NmA but I some W135, Tandjile region, Bere district. March–May 2007: 31 cases; 3 deaths; CFR 9.7%; NmA, Salamat region, Am Tinman district. March–April 2006: 152 cases; 9 deaths; CFR 5.9%; NmA, Mayo-Kebbi-East II and Logone oriental regions, Fianga and Doba districts. January–March 2005: 293 cases; 29 deaths; CFR 9.8%; Nm A, Mayo-Kebbi-East and Mandoul regions, Bongor and Moissal districts. January 2005: 9 cases; no deaths; Nm W135, Ouaddai region, refugee camps III in Brejing, Farchana and Treguine, Adre district. April 2004: 19 cases; 4 deaths; CFR 21%; NmA, Wadi Fira region, Iriba district. IV Dec 2000 – March 2001: 3579 cases; 401 deaths; CFR 11.2%; NmA, Moyen Chari, Mayo Kebb, Logone oriental and Logone occidental.

Communicable disease epidemiological profile 128 CENTRAL AFRICAN REPUBLIC AND CHAD bulging fontanelle. bulging by a accompanied fever is when meningitis <1year, suspect aged patients In or more of the following: or following: more of the one and of> sudden °C axillary) onset 38.0 fever (> with °C rectal, 38.5 illness An definition case Clinical definition Case Bacterium: Infectious agent Description Communicable disease epidemiological profile epidemiological disease Communicable of infection. source important most the are carriers asymptomatic therapy, of but institution the after hours 24 until of symptoms onset From the period Communicability anddays). 4 days 2 10 commonly (most between varies period incubation The Incubation period droplets. respiratory with contact Direct Mode of transmission classification Case criteria Laboratory

Confirmed: a suspected or probable case with laboratory-confirmation. with case or probable suspected a Confirmed: and above; defined as case asuspected Probable: above. definition case clinical the meets that acase Suspected: culture. bacterial positive or detection; fluid antigen (CSF) Positive cerebrospinal rash. or purpural or petechial sign meningeal other consciousness; altered stiffness; neck

continuing epidemic. epidemic. continuing or stain); Gram positive or without (with CSF turbid serogroups A, B, C, Y, C, B, A, W135. serogroups meningitidis Neisseria 129 Epidemiology General The highest burden of meningococcal disease occurs in sub-Saharan Africa in an area known as the “meningitis belt” that lies between Senegal and Ethiopia and includes all, or part of, at least 15 countries of which CAR and Chad. Twelve subtypes or serogroups of Neisseria meningitidis have been identified and four (N. meningitidis A, B, C and W135) are recognized as causing epidemics. The pathogenicity, immunogenicity, epidemic capabilities and vaccines differ according to the serogroup. Thus the identification of the serogroup responsible for a sporadic case is crucial for epidemic containment. In 1996, Africa experienced the largest recorded outbreak of epidemic meningitis in history, with over 250 000 cases and 25 000 deaths registered. Between 1996 and 2002, a further 223 000 new cases of meningococcal meningitis were reported to WHO. The countries most affected were Burkina Faso, Chad, Ethiopia and Niger. The meningitis belt also appears to be extending further south. In 2002, the Great Lakes region was affected by outbreaks in villages and refugee camps that caused over 2200 cases, including 200 deaths. In major African epidemics, attack rates range from 100 to 800 per 100 000 population, but individual communities have reported rates as high as 1000 per 100 000. MENINGOCOCCAL SEPTICAEMIA) AND MENINGOCOCCAL DISEASE (MENINGITIS While in endemic disease the highest attack rates are observed in young children, during epidemics, older children, teenagers and young adults are also affected.

Geographical distribution I Chad and CAR are in the African meningitis belt, an area that experiences repeated epidemics of meningococcal disease, in addition to the substantial number of endemic cases. II Seasonality Epidemics of meningococcal disease occur in seasonal cycles between the end of November and the end of June. Dry, windy and dusty seasons increase transmission of the disease. Conversely rains decrease transmission. III Alert threshold Population > 30 000: 5 cases per 100 000 inhabitants per week or a cluster of cases in an area. IV Population < 30 000: 2 cases in 1 week or an increase in the number of cases compared with previous non-epidemic years.

Communicable disease epidemiological profile 130 CENTRAL AFRICAN REPUBLIC AND CHAD Epidemic threshold 6. 5. 4. 3. 2. 1. Intervention: Communicable disease epidemiological profile epidemiological disease Communicable or because emergencies, during Crowding for outbreaks. factors risk important Overcrowding. to country. country or from acountry, within strains of virulent tion circula the facilitate displacement and Travel, migration movement. Population Risk factors for increased burden Intervention:

Prepare. Inform the public. the Inform protocol to epidemic Treat according centres to health treatment Distribute vaccination Mass or 1week, in occur 5cases 000: <30 Population if week per inhabitants 100 000 per 10 cases 000: >30 Population Strengthen surveillance surveillance Strengthen Treat cases Confirm Investigate authorities Inform Other situations should be studied on a case-by-case basis. on acase-by-case studied be should situations Other 15 cases per 100 000 inhabitants per week in other situations. other in week per inhabitants 100 000 per 15 cases

1 week are enough to initiate vaccination of the population. of the vaccination to initiate enough are 1 week in cases 2confirmed persons, displaced and refugees gatherings, for mass or a3-week period; in of cases number weekly of the doubling alert threshold crossed early in the dry season. dry the in early crossed threshold alert <80%; coverage vaccination and forno epidemic 3years Crowding of susceptible people and poor indoor ventilation are are ventilation indoor poor and people of susceptible Crowding - 131 of cattle or fishing-related activities, or in military camps and schools, facilitates spread of the disease. Poor access to health services. Case identification is crucial for rapid implementation of control measures. The case-fatality ratio in the absence of treatment can be very high (50%).

Prevention and control measures Enhanced epidemiological surveillance and prompt case management with oily chloramphenicol and reactive mass vaccination campaigns are used to control epidemics. Routine immunization is not possible with currently available vaccines, as polysaccharide vaccines only provide protection for 3–5 years and cannot be used in children aged < 2 years since current meningococcal vaccines are not immunogenic in this age group (i.e. no antibodies are produced). Even large-scale coverage with current vaccines does not provide sufficient “herd immunity”. Concurrent infections: upper respiratory tract infections may increase transmission of meningitis.

Low vaccination coverage (< 80%) increases the number of susceptible people in MENINGOCOCCAL SEPTICAEMIA) AND MENINGOCOCCAL DISEASE (MENINGITIS the population. Consequently, the current WHO recommendation for outbreak control is mass vaccination in every district that is in an epidemic phase, as well as those contigu- I ous districts that are in the alert phase. It is estimated that a mass immunization campaign, promptly implemented, can avoid 70% of cases.

Case management II Meningococcal disease (either meningitis or septicaemia) is potentially fatal and should always be considered a medical emergency.

Non-epidemic conditions III Admission to a hospital or health centre is necessary for diagnosis (lumbar puncture and CSF examination). Lumbar puncture must be done as soon as meningitis is suspected, before starting antimicrobials. IV As infectivity of patients is moderate and disappears quickly following antimicrobial treatment, isolation of the patient is not necessary.

Communicable disease epidemiological profile 132 CENTRAL AFRICAN REPUBLIC AND CHAD tive and is preferred for mass interventions during epidemics. epidemics. during interventions for preferred is mass and tive effec be to shown been also has The long-acting (oily) chloramphenicol of form ( meningitis bacterial of causes major three the against effective be should therapy antimicrobial Initial Communicable disease epidemiological profile epidemiological disease Communicable established: been has disease of meningococcal diagnosis Once Initial empirical antimicrobial therapy for presumed bacterial meningitis bacterial presumed for therapy antimicrobial empirical Initial influenzae Neonates 1 month to 5years to 1 month Children > 5years children and Adults situations Non-epidemic All age groups age All situations Epidemic Age group Age

A 7-day course is the general rule for treatment of meningococcal disease beyond beyond disease period. neonatal the meningococcal of treatment for rule general the is course 7-day A more expensive. alittle but are alternatives excellent are cefotaxime, and ceftriaxone cefalosporins, third-generation The tests. susceptibility on antimicrobial based antibiotics or other injection chloramphenicol or ampicillin includebenzylpenicillin, choiceof drugs The treatment. supportive with combined be should and results) for laboratory (without waiting puncture lumbar after possible as soon as instituted be must therapy Antimicrobial ) until bacteriological results are available (see below). available are results bacteriological ) until N. meningitidis Listeria Bstreptococci Group bacteria Gram-negative N. meningitidis N. pneumoniae S. influenzae H. S. pneumoniae S. meningitidis N. N. meningitidis N. Probable pathogens Probable spp. Haemophilus Haemophilus and pneumoniae , Streptococcus Ampicillin and Ampicillin chloramphenicol chloramphenicol or amoxycilin or Ampicilin oily chloramphenicol chloramphenicol oily or Benzylpenicillin oily chloramphenicol oily or Benzylpenicillin First choice First gentamicin gentamicin Antimicrobial therapy Antimicrobial

chloramphenicol chloramphenicol or cefotaxime or Ceftriaxone cefotaxime cefotaxime or Ceftriaxone co-trimoxazole or cefotaxime or ceftriaxone or Ampicillin co-trimoxazole or cefotaxime or ceftriaxone or Ampicillin Alternative

- 133

Epidemic conditions During epidemics of confirmed meningococcal disease, case management needs to be simplified to permit the health system to respond to rapidly increasing numbers of cases.

Diagnosis: as the flood of patients could make the routine use of lumbar puncture to confirm meningitis impossible, every suspected case of meningitis should be considered and treated as having meningococcal meningitis. Treatment: long-acting oily chloramphenicol (100 mg/kg up to 3 g in a single dose) given intramuscularly, is the drug of choice for all age groups, particularly in areas with limited health facilities. For those who do not improve rapidly, an additional dose of the same antimicrobial 48 hours after the first dose is recommended.

Reactive vaccination A mass vaccination campaign may halt an epidemic of meningococcal disease if carried out appropriately. Laboratory diagnosis and confirmation of epidemic serogroups will guide the type of vaccine needed, either meningococcal polysaccharide bivalent A/C (if serogroup A or C is confirmed as the epidemic serogroup), menin- MENINGOCOCCAL DISEASE (MENINGITIS AND MENINGOCOCCAL SEPTICAEMIA) AND MENINGOCOCCAL DISEASE (MENINGITIS gococcal polysaccharide trivalent A/C/W135 (if serogroup W135 is confirmed) or tetravalent vaccine A/C/Y/W135 (if serogroup Y or W135 is confirmed). Vaccination should be concentrated in the area where the epidemic is maximal. I Camp settings: following confirmation (serogroup identified) of two cases, mass vaccination is recommended if the serogroup(s) identified is(are) included in either the bivalent (A/C) or tetravalent (A/C/Y/W135) vaccine. At-risk populations (e.g. 2–30 years of age) should be given priority. II General population: if an outbreak is suspected, vaccination should be considered only after careful investigation (including confirmation and serogroup identification) and assessment of the population group at highest risk.

Chemoprophylaxis of contacts of meningitis patients is not warranted during an III epidemic. In small clusters or outbreaks among closed populations (e.g. extended household, boarding schools), chemoprophylaxis may still be appropriate. IV

Communicable disease epidemiological profile 134 CENTRAL AFRICAN REPUBLIC AND CHAD tegic plan for integrated control of helminth infections, including onchocerciasis. onchocerciasis. including infections, of control helminth for integrated plan tegic astra developed recently has country the support, WHO With initiative. control Africa-wide of an part 1997 as in (APOC) commenced Control for Onchocerciasis Programme African The unrest. of civil aresult as in1996 1993 but were interrupted in began an Christoffel-Blindenmission) NGO by sponsored (the first operations in Control the endemic be to 11 known of 16 regions. is onchocerciasis affected, of villages number the done to be to update needs still mapping further Although unrest. civil to owing interruption 5-year a after activities distribution ivermectin mass of relaunch the country to support representative WHO the of office the (APOC) in Control for Onchocerciasis Programme African by the placed been has adviser atechnical 2007 Since at risk. are people 1.5 million Approximately Central African Republic Country-specific disease burden ONCHOCERCIASIS (RIVER BLINDNESS) Communicable disease epidemiological profile epidemiological disease Communicable may experience: ciasis from onchocer People suffering or ganglia. nodes lymph from distinguished be must These tissues. subcutaneous in fibrous nodules with aperson area, endemic an In description Clinical definition Case volvulus Onchocerca Infectious agent Description 75% 7years. past over the averaged Treatment has coverage of APOC. auspices the under mainly treatment, drug for mass annually targeted are people 1.6 million Approximately country. the of part southern in 7 the of endemic is in 18 regions (17disease districts) The Chad

larvae as they migrate subcutaneously or to their destruction in the skin. the in destruction or to their subcutaneously migrate they as larvae motile to the reaction to tissue secondary are changes dermal lesions: Skin , a filarial worm belonging to the class Nematoda class the to belonging worm , afilarial . - - 135

Itching: the pruritus of onchocerciasis is the most severe and intractable that is known. In lightly-infected individuals, this may persist as the only symptom. Rashes: the rash usually consists of many raised papules, which are caused by microabscess formation, and may disappear within a few days or may spread. Sowda, from the Arabic for black or dark, is an intensely pruritic eruption usually limited to one limb and including oedema, hyperpigmented papules and regional lymphadenopathy. Depigmentation of the skin: areas of depigmentation over the anterior shin, with islands of normally pigmented skin, commonly called “leopard skin”, are found in advanced dermatitis. Subcutaneous nodules: these are asymptomatic subcutaneous granulomas, 0.5–3.0 cm, resulting from a tissue reaction around adult worms. They occur most frequently over bony prominences: in Africa, the nodules are often located over the hips and lower limbs. Lymphadenopathy: frequently found in inguinal and femoral areas, lymphadenopathy can result in “hanging groin” (especially when associated with skin atrophy and loss of elasticity) and elephantiasis of the genitalia.

Eye lesions: ocular onchocerciasis is related to the presence of live or dead microfilariae. Involvement of all tissues of the eye has been described, and many changes BLINDNESS) (RIVER ONCHOCERCIASIS in both anterior and posterior segments of the eye may occur. The more serious lesions lead to serious visual impairment including blindness. General debilitation: onchocerciasis has also been associated with weight loss and I musculoskeletal pain.

Laboratory criteria Presence of one or more of the following: II

microfilariae in skin snips taken from the iliac crest (Africa) or scapula (Americas); adult worms in excised nodules; typical ocular manifestations, such as slit-lamp observations of microfilariae III in the cornea, the anterior chamber or the vitreous body; serology (especially for non-indigenous people).

Case classification IV Suspected: a case that meets the clinical case definition. Confirmed: a suspected case that is laboratory-confirmed.

Communicable disease epidemiological profile 136 CENTRAL AFRICAN REPUBLIC AND CHAD infective bite. infective the of time the from or more 1 year only after usually skin the in found are of Microfilariae period a 7–34 months. after found may be wherethey tissue, ocular and skin in of microfilariae death by the caused are infection O. volvulus sequelae of pathological main infection). The after 1year as early as develop (these can nodules subcutaneous of the production the from apart innocuous, Incubation vector. insect the in O. volvulus with together but may occur humans infect Onchocerca Other reservoir. only the are Humans (see above). symptoms ocular and of dermal avariety producing eyes, the through and skin the under migrate that of microfilariae millions produces female adult Each nodules. subcutaneous of forms whereadult body human the in parasites adult into develop larvae Infective meal. blood bite of wound asubsequent the during skin human into liberated to be sule cap cephalic the to migrate days several after and larvae infective into develop fly.the them of afewthoracic Here, of muscles the penetrate then microfilariae these person; infected an on feeding by a blackfly ingested are Microfilariae flight. in of kilometres may cover hundreds they time which during for up live to 4weeks, 8–12 and days after emerge blackflies Adult blindness”. thename “river thus – rivers fast-flowing neavei S. some foci but in damnosum S. the Simuliumgenus to belonging blackflies female bite of infected the by another to carried are in person one produced microfilariae Onchocercal Mode of transmission Communicable disease epidemiological profile epidemiological disease Communicable period Communicability

may live for up to 14–15 years and are often found encased in fibrous fibrous in for may up live encased to 14–15 found often O. are volvulus and years infective larvae) 7–9 days after the blood meal. themeal. blood 7–9 after larvae) days infective transmit able to (i.e. infective become vectors blackfly to human: Blackfly worms. the adult of death the after for up to 2 maypersist years They larvae. of infective introduction of 7–34prepatent period following months a after skin (about worms the day), per female in found may 700 be adult and by produced are continuously Microfilariae skin. their in occur microfilariae living as as long blackflies infect may individuals infected to blackfly: Human . Larvae take at least 6–12 months to mature. Adult worms are usually usually are worms Adult 6–12 to mature. months at least take . Larvae ). The blackfly lays its eggs in the water of the in eggs its lays ). The blackfly species found in animals cannot cannot animals in found species (mainly (mainly

137 Risk factors for increased burden Population movement. Migration of infected people from areas where transmission is still ongoing could result in resurgence of onchocerciasis in areas previously free of the disease. Overcrowding increases the risk of infectious bites.

Other factors The great majority (99%) of the 37 million people thought to be infected live in 30 countries in sub-Saharan Africa. Onchocerciasis is not a fatal disease, but its consequences may be severe if it is left untreated. These include disfigurement, severe itching, skin depigmentation (which may hinder social integration) and, most devastatingly, vision impairment and eventual blindness. Onchocerciasis also has important socioeconomic consequences. Fear of blindness has led to depopulation of fertile river valleys of the western African savannah, greatly diminishing agricultural production and increasing poverty and famine. The dramatic consequences of onchocerciasis in western Africa led WHO, in collaboration with other agencies including the World Bank, the United Nations Development ONCHOCERCIASIS (RIVER BLINDNESS) (RIVER ONCHOCERCIASIS Programme (UNDP) and the Food and Agriculture Organization of the United Nations (FAO) to launch the Onchocerciasis Control Programme (OCP) in 1974. The programme operated over 1 200 000 km² and worked to protect 30 million people in 11 countries from the debilitating effects of river blindness. OCP was I officially closed in December 2002 after virtually stopping transmission of the disease in all the participating countries except Sierra Leone, where operations were interrupted by a decade-long civil war. Currently, there is little risk of infection, however disease surveillance needs to II continue with focus on those areas into which migration is occurring.39

Prevention and control measures III Case management Administration of ivermectin once a year over a period of at least 15–20 years will reduce infection to insignificant levels and prevent the appearance of clinical IV 39 Guidelines for rapid assessment of Loa loa. Geneva, WHO, 2002 (TDR/IDE/RAPLOA/02.1; http://www. who.int/tdr/publications/publications/pdf/loaguidelines.pdf).

Communicable disease epidemiological profile 138 CENTRAL AFRICAN REPUBLIC AND CHAD Treatment with ivermectin is contraindicated in: contraindicated is ivermectin Treatment with by ivermectin. treated also are manifestations clinical Established of formulation). 3mg 1–4 tablets using to height, according is dosage (in practice, weight body µg/kg to 150 equivalent is dosage The recommended manifestations. Communicable disease epidemiological profile epidemiological disease Communicable programmes. treatment ivermectin include could and occurs migration which into on areas focus should prevent resurgence to of 75%. coverage Efforts atherapeutic with Ethiopia in ivermectin with treated people were million 3 than more 2005, in for up to a year. example, For filariae micro skin of numbers the reduces greatly that microfilaricide effective an is Ivermectin time. first for the of onchocerciasis treatment for large-scale regimen chemotherapeutic in a feasible 1987 provided ivermectin of introduction The weight). body (150 μg/kg of ivermectin administration once-yearly the involves CDTI (CDTI) ivermectin with treatment (2) Community-directed OCP.the of strategy thebasic was This disease. of the source the eliminating thus population, human the out in dies worms of adult for 14–15 reservoir the years, interrupted been has cycle the Once transmission. of disease cycle the to interrupt in order rivers, fast-flowing in sites to breeding spraying aerial (Abate®) through of Simulium Destruction (1) Vector control forThetwostrategies main prevention and control are: of inAfrica onchocerciasis Prevention coverage. treatment good maintain programmes treatment mass if administration by ivermectin managed be can and may occur of transmission Recrudescence Epidemiccontrol

severely ill people. ill severely old; 1week than less of infants mothers lactating women; pregnant (age), (height); cm 15(weight), 90 <5years kg than than children less or less larvae by application of insecticides such as temephos temephos as such of insecticides by application larvae - 139 PERTUSSIS (WHOOPING COUGH)

Country-specific disease burden Central African Republic

Reported cases, Central African Republic, by year

Year 2007 2006 2005 2004 2003 2002 2001

02 65 87 561 80 10 1 358

Source: WHO vaccine-preventable diseases monitoring system, 2008 global summary (as of 1 August 2008) (http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidenceper.htm).

Chad No data are available.

Description Infectious agent PERTUSSIS (WHOOPING COUGH) Bordetella pertussis, the pertussis bacillus.

Case definition I Clinical description The initial stage – the catarrhal stage – is characterized by coryza (runny nose), sneezing, low-grade fever and a mild, occasional cough, similar to the common cold. It has an insidious onset, with an irritating cough that gradually becomes II paroxysmal, usually within 1–2 weeks, and lasts for 1–2 months or longer. The patient has bursts, or paroxysms, of numerous rapid coughs, apparently caused by difficulty in expelling thick mucus from the tracheobronchial tree. At the end of the paroxysm, a long inspiratory effort is usually accompanied by a III characteristic whoop. In younger infants, periods of apnoea (cessation in breathing) may follow the coughing spasms, and the patient may become cyanotic (turn blue). The disease lasts 4–8 weeks. In the convalescent stage, recovery is gradual. The cough becomes less paroxysmal. However, paroxysms often recur with subsequent IV respiratory infections for many months after the onset of pertussis. Fever is generally minimal throughout the course of pertussis.

Communicable disease epidemiological profile 140 CENTRAL AFRICAN REPUBLIC AND CHAD Clinical case definition case Clinical disease. have milder but usually pertussis, B. with infected may become vaccine, by the protected partially those adults), and (i.e. and adolescents Older individuals 1–4 years. 1% aged for children and <1year aged at 3.7% for children estimated are rates case-fatality countries, developing In infants. younger in severe more and frequent are Complications more rarely. occur death and encephalopathies convulsions, epistaxis), and petechiae conjunctival (sub haemorrhages Otitis, pneumonia. include commonly most Complications Communicable disease epidemiological profile epidemiological disease Communicable cases. pertussis multiple with ina household case first the be to found often are Adults infants. immunized or under- non-immunized including individuals, susceptible to other disease the may people transmit infected these older individuals, in milder may be disease the Although hosts. only the are route. Humans airborne the via people of infected mucous membranes respiratory from discharges with contact by direct Primarily Mode of transmission classification Case criteria Laboratory

Confirmed case: a clinical case that is laboratory-confirmed. is that case clinical a case: Confirmed definition. case clinical the meets that acase case: Suspect serology. Positive paired (PCR); reaction chain by polymerase of genomic sequences Detection pertussis of B. Isolation symptoms: atone least of following with at2 the weeks least lasting a cough a with person or by aphysician; pertussis as diagnosed A case

other apparent cause. apparent other without coughing) after immediately (i.e. vomiting vomiting post-tussive paroxysms (i.e. fits)coughing; of paroxysms inspiratory “whooping”; inspiratory ; - 141

Incubation period The incubation period usually lasts 7–10 days and rarely more than 14 days.

Communicability period Pertussis is highly communicable in the early, catarrhal stage (90%). Communi- cability gradually decreases after the onset of the paroxysmal cough. Patients may be contagious for up to 3 weeks after the onset of paroxysmal cough in the absence of treatment, or up to 5 days after onset of treatment.

Epidemiology General Outbreaks of Bordetella pertussis are common in settings of population displacement, but definitive laboratory evidence is rare. This may be because of the difficulty of obtaining laboratory-confirmation from suspected cases. Risk factors for transmission in settings such as those found in CAR include low levels of routine immunization (2005 estimates of DTP3 coverage < 40%), crowding, malnutrition, and coinfection with other illnesses (HIV, malaria, tuberculosis, etc.). Fluctuations in the number of reported cases reflect a weak surveillance system and may mask PERTUSSIS (WHOOPING COUGH) the actual number of cases. Examples of outbreaks that have occurred in humanitarian settings are: I 1. Democratic Republic of the Congo, January 1999 – February 2000: 1136 cases, including 23 (2%) deaths. Vaccination coverage (DTP1) of infants < 12 months in the affected area was estimated to be 32%. Response activities consisted of case-management support with provision of erythromycin, active surveillance, II and strengthening of routine EPI services. A vaccination campaign following the outbreak was not well accepted by the population, owing to fears of secondary effects. 2. Democratic Republic of the Congo, 2001: 2633 cases, including 17 (0.6%) III deaths. 89% of the cases were ≤ 5 years of age. Cases were defined as having the characteristic coughing fits, “whooping”, and vomiting after coughing for ≤ 2 weeks (suspect case) or longer than 2 weeks (probable case). Suspect cases were treated with erythromycin for 2 weeks. A vaccination campaign IV in one village targeted children 6–72 months old and covered 81% of the targeted population.

Communicable disease epidemiological profile 142 CENTRAL AFRICAN REPUBLIC AND CHAD outbreaks, although high vaccination coverage may prolong the interepidemic intervals. interepidemic may prolong coverage the vaccination high although outbreaks, of pertussis occurrence the allow adults and adolescents Susceptible infants. young to non-immunized pertussis B. transmit and infection for the reservoirs as may serve immunity waning with older individuals and children non-immunized Remaining coverage. vaccination high with countries in even pertussis, of B. circulation on the impact limited has a vaccine the disease, clinical efficient its prevention of Despite vaccination. fortion pertussis acontraindica may be encephalitis previous that perception the to support data are no There pertussis. against immunized be should HIV-positive individuals, including infants, All vaccine. to this contraindications no strict are there tion, reac anaphylactic in resulted vaccination whereprior pertussis for cases Except 100 0.9 000. per is encephalopathy pertussis-associated incidence of The <6months. aged those in frequently most occur bronchopneumonia, notably most 15%. may reach CFR Complications, the fections, of coin prevalence high with populations unvaccinated However malnourished in infants. immune non- young very in reported mainly is death and 1–14 disease Severe year-olds. 1% and in infants 3.9% in is CFR average the countries however developing in low is very (0.1%),countries industrialized in pertussis of ratio case-fatality The 5. 4. 3. Communicable disease epidemiological profile epidemiological disease Communicable available. are reported of cases distribution geographical of the No details distribution Geographical

5 years of age was accelerated in the affected areas. affected the in accelerated was of age < 5years of children vaccination Routine erythromycin. with contacts and of cases treatment mass 13 included (3.1%) including 419 2005: activities cases, Response Sudan, deaths. and all children and contacts in the affected families using erythromycin. using families affected the in contacts and children all and of cases treatment door-to-door mass included measures Outbreak-control services. not covered by health remote counties two in lived populations affected The pertussis. as diagnosed but clinically diagnosis laboratory tive no defini deaths, 300 including unknown, is of cases number the 2004: Sudan, in 5 affected subdistricts, involving villages. involving 189 subdistricts, 5affected in of age 15 of or symptoms) presence years under cases, with contact status, tion of immuniza (regardless children to all given was of erythromycin regimen treatment A10-day of <40%. coverage vaccination estimated with population 17 (14.8%) including border 115 2003: isolated an cases, in deaths Afghanistan,

- - - - - 143

Seasonality Pertussis has no distinct seasonal pattern, but activity may increase in the summer and autumn.

Alert threshold One case is sufficient for an alert and must be investigated, especially if the case occurs in high-risk areas (i.e. with low vaccination coverage).

Risk factors for increased burden Population movement facilitates the spread of B. pertussis. Overcrowding. Crowded conditions facilitate transmission. The disease is usually introduced into a household by an older sibling or a parent. Poor access to health services may also mean no access to routine immunization services. Susceptibility of non-immunized individuals is universal, and vaccination is the mainstay of pertussis control. Low vaccination coverage is a major risk factor for increased transmission (diphtheria−tetanus−pertussis vaccine (DTP3) coverage is < 40% in Chad and < 20% in CAR). PERTUSSIS (WHOOPING COUGH)

Prevention and control measures Case management I The drug of choice for the treatment of pertussis is erythromycin or erythromycin estolate, which should be administered for 7 days to all cases and close contacts of people with pertussis, regardless of age and vaccination status, and for all those living in households where there is an infant aged < 1 year. Clarithromycin II and azithromycin are also effective. Drug administration both modifies the course of illness (if initiated early) and eradicates the organism from secretions, thereby reducing communicability, but does not reduce symptoms except when given during the catarrhal stage or early III in the paroxysmal stage. Symptomatic treatment and supportive case management are important.

Immunization IV Vaccination is the most effective way to control pertussis. Active primary immunization against B. pertussis infection with the whole-cell vaccine (wP) is recommended

Communicable disease epidemiological profile 144 CENTRAL AFRICAN REPUBLIC AND CHAD up to date. and brought verified status immunization have must their contacts and cases All first. comes whichever of cough, theend until or cough, paroxysmal of onset after or for up to 3weeks treatment commencing for after up to 5days grouped, are individuals where susceptible places other and schools centres, day-care avoidwith must contact cases Index case. index the with contact first the following of a maximum relies onwithin of14Thechemoprophylaxis days contacts strategy wane after about 3 years. about 3 years. after wane to begins and disease severe against greater is Protection 80%. to exceed mated esti is doses 3 least received at who have children in vaccine the of efficacy The older children. in severe less is disease the and adults and older children in increased may be reactions local since or older, 7years aged (wP) vaccine to individuals not is given pertussis general, In of choice for some countries. vaccines the are andvaccines wP use, their affect considerations price reactions, adverse with (aP) associated commonly less vaccines is of acellular use the Although available. is vaccine pertussis No single-antigen available. are resources if of 2years age at the dose 10 afourth at 6, 14 and and of age, weeks toxoids (DTP) tetanus and of diphtheria administration the with association in Communicable disease epidemiological profile epidemiological disease Communicable to: given be should Priority cases. individual to selected treatment prophylactic limit all resistance of drug occurrence to the related concerns and involved costs nosis, diag early of but difficulties may prevent disease, period incubation early the in cases among non-immune contacts. Prophylactic antibioticsecondary of numbers large to leads disease the of treatmentnature contagious highly The (erythromycin) Epidemiccontrol

pregnancy. of 3 weeks final the women in pregnant and of age 1year under children include these if particularly household members, among infection stopping 3 weeks of pregnancy because of the risk of transmission to the newborn; and newborn; to the of transmission risk of the because of pregnancy 3 weeks final the in females pregnant and of age 1year under children protecting -

- 145 POLIOMYELITIS

Country-specific information Central African Republic The last polio case was reported in April 2008.

Polio cases reported nationally, Central African Republic, 2001–2008

Year 2008 2007 2006 2005 2004 2003 2002

3 0 0 0 30 1 0

Source: Polio Eradication Initiative, data as of 23 July 2008 (http://www.polioeradication.org/http://www.who. int/immunization_monitoring/en/globalsummary/timeseries/tsincidencepol.htm).

Since 2001, CAR has been free of indigenous poliovirus but has experienced successive importations of wild poliovirus (WPV) type 1 from Chad during 2003–2004, leading to an outbreak that was successfully stopped. In April 2008, CAR experienced further importation of WPV-1 from the Democratic Republic of the Congo (Bangui commune). As of 11 August 2008, there has been no further evidence of virus circulation in CAR. POLIOMYELITIS Surveillance indicators are of certification quality at national level. However at provincial level quality began to deteriorate in the north and west of the country from mid-2007. The non-polio acute flaccid paralysis (AFP) rate was suboptimal in the western and northern parts of the country for the 6 months prior to and I including December 2007. For the period January–July 2008, the non-polio AFP rate for the western part of the country remained suboptimal. The current situation contributes to weakened surveillance and routine immunization activities. In response to this concern and the recent importation of WPV-1 in Bangui, the II polio eradication programme has planned national immunization days (NIDs) in 2008 using trivalent oral polio vaccine (OPV) and monovalent OPV. These activities may be limited as a result of security issues. Chad III Polio cases reported nationally, Chad, 2001–2008

Year 2008 2007 2006 2005 2004 2003 2002 2001 37 21 1 2 24 25 0 0 IV Source: Polio Eradication Initiative, data as of 23 July 2008 (http://www.polioeradication.org/http://www.who. int/immunization_monitoring/en/globalsummary/timeseries/tsincidencepol.htm).

Communicable disease epidemiological profile 146 CENTRAL AFRICAN REPUBLIC AND CHAD be security- and access-dependent. and security- be will activities mOPV3 mOPV1These December. November tOPV and in in and mOPV1 using and 2008 during activity SIA some staggered planning is Chad activities. of planned precipitate may cancellation even and shortfalls to such tribute con further will circumstances Current some areas. in movements insecurity and population management, campaign poor systems, health subnational weakened by caused children, missed many (SIAs) with activities immunization mentary suppleof quality maybe suboptimal due to Chad in transmission persistent The population). 25% total of the people, million (a of 2.23 total N’Djamena and Lac Hadjer-Lamis, Chari-Baguirmi, in indicators Wadi-Fira, but and suboptimal Ouaddai Moyen Chari, Kanem, in performance surveillance good indicate data 2008, to June 2007 From July flict. con current by the exacerbated may be and gapsexist surveillance subnational However, level. national at surveillance certification-standard reached has Chad East. Middle the and of Horn Africa to the Nigeria from spread WPV when 2004–2005 in link key a was Chad that given concern is particular of The situation Sudan. bouring 1to neigh type WPV 2007, late In exported Chad excluded. be WPV1 cannot of circulation ongoing of surveillance, quality However, suboptimal to the owing in 2007.November had onset case 1 type WadiWPV Fira).last The Ouaddai, N’Djamena, occidental, Logone Kanem, (Hadjer-Lamis, 6regions from cases 12 (WPV-3) reported had Chad 2008, of 19 As August Nigeria. from notably tions, importa successive following outbreak amajor polio experienced Chad 2008, In Communicable disease epidemiological profile epidemiological disease Communicable such symptoms, neuromuscular and of meningitic onset abrupt followed by the fever may be afew cases, In disease. of the phase viraemic to the corresponding days, a few lasting illness febrile anonspecific report cases symptomatic Most (at 95%) least asymptomatic. remain infections most although paralysis, may cause poliovirus of wild types three All description Clinical definition Case ( Poliovirus Infectious agent Description Enterovirus group): types 1, 3. 2, group): types - - - - - 147 as stiffness in the neck and pain in the limbs. Initial symptoms may also include fatigue, headaches, vomiting and constipation (or, less commonly, diarrhoea). In a very small percentage of cases (≤ 1% of infected susceptible individuals), the gradual onset (2–4 days) of flaccid paralysis may then follow. Paralytic disease usually affects the lower limbs and is typically asymmetric and more severe proximally (at the tops of the legs). Bulbar (brainstem) paralysis may also occasionally occur, leading to respiratory muscle involvement and death unless artificial respiration is used. Mortality from paralytic poliomyelitis is between 2% and 10%, mainly as a result of bulbar involvement and/or respiratory failure. Risk factors for paralytic disease are a large inoculum of virus, increasing age, pregnancy, recent tonsillectomy, strenuous exercise and intramuscular injections during the incubation period. After the acute illness, there is often a degree of recovery of muscle function; 80% of eventual recovery is attained within 6 months, although recovery of muscle function may continue for up to 2 years. After many years of stable neurological impairment, new neuromuscular symptoms develop (weakness, pain and fatigue, post-polio syndrome) in 25–40% of patients.

Clinical case definition Acute flaccid paralysis (AFP) in a child aged < 15 years, including Guillain– POLIOMYELITIS Barré syndrome;* or any paralytic illness in a person of any age when polio is suspected. I * For practical reasons, Guillain–Barré syndrome is considered as poliomyelitis until proven otherwise.

Laboratory criteria Isolation of wild poliovirus in stool sample. II Case classification Suspected: a case that meets the clinical case definition. Confirmed: AFP with laboratory-confirmed wild poliovirus in stool sample. III Polio-compatible: AFP clinically compatible with poliomyelitis, but without adequate virological investigation.

Mode of transmission IV Poliovirus is highly communicable. Transmission is primarily person to person via the faecal–oral route.

Communicable disease epidemiological profile 148 CENTRAL AFRICAN REPUBLIC AND CHAD These include the following: the following: include These site. manufacturing or a vaccine ratory labo aresearch from either environment, the into escaping poliovirus of awild risk the to minimize of activities anumber to conduct required are countries All Priorities include: Priorities importation. poliovirus wild of any to avoid detection late in order maintained widely is surveillance standard certification that important It therefore is countries. to polio-endemic proximity geographical of their less regard of importations, at risk remain countries All strategies. eradication to polio challenges represent considerable priorities competing and Weak infrastructure General Epidemiology weeks. 4–6 for infection, after From hours 36 period Communicability days. 4–30 is paralysis of and onset infection between time The Incubation period Communicable disease epidemiological profile epidemiological disease Communicable

under appropriate biosafety conditions, or being destroyed. or being conditions, appropriate biosafety under secured stocks poliovirus wild the with process ofcompletion containment WHO; to report survey biomedical of finalized submission polioviruses; hold wild which certainty with determine to facilities biomedical identified of all surveying stock; virus polio hold wild could which facilities biomedical of all of alist compilation coordinator; containment of anational appointment Immunization. on Programme Expanded the for infrastructure basic improving (SIAs); activities immunization tary of supplemen to improve targeting surveillance AFP high-quality sustaining of conflict; aresult as inaccessible are that those including areas, to all access gaining and children non-immunized previously reaching - - - 149

This stage is to be commenced 1 year after the global interruption of wild poliovirus transmission.40 With transborder population movements, there is a risk of the poliovirus being exported to CAR which has remained polio-free since 2004, as well as other neighbouring countries. It is likely that the current outbreak in Chad implies that circulation of the virus has not been completely arrested since 2003–2005 in spite of 14 national immunization days and 8 subnational immunization days. Chad has attained the certification standard for AFP surveillance indicators since 2005, with non-polio AFP rates of ≥ 2 per 100 000 in the < 15 population and of ≥ 80% stool samples taken within 14 days of paralysis onset. Nevertheless, subnational surveillance gaps exist and may be exacerbated by current conflict: 2007 data indicates good surveillance performance in Kanem, Ouaddai, Moyen Chari and Wadi-Fira, but suboptimal indicators in N’Djamena, Chari- Baguirmi, Lac and Hadjer-Lamis (2.23 million people, i.e. 25% of the total population). While the majority of WPV isolates were type 1, 2 cases (1 in 2006 and 1 in 2007) were type 3. The former was determined to have been a direct importation from Nigeria, while the latter may have circulated in Chad or elsewhere for some time.

In September 2007, a case of WPV genetically linked to circulating viruses in POLIOMYELITIS Abeche was detected in the South Darfur region of Sudan, further highlighting the risk that the ongoing outbreak in Chad represents for neighbouring countries. The observed persistent transmission in Chad may be due to suboptimal quality I of SIAs with many missed children occasioned by weakened subnational health systems, poor campaign management, population movements and insecurity in some areas. Current circumstances will further contribute to such shortfalls and may even precipitate cancellation of planned activities. II After the November 2007 NIDs, 18 of 55 districts were surveyed for coverage. On average, 14% of the children were found to have been missed, with 12 out of 18 districts having over 10% missed children. Similarly, as an indication of population immunity, less than 50% of non-polio AFP cases had ≥ 4 doses of OPV in 2007. III Since August 2007, WHO has added 11 international consultants to assist with the planning, preparation and supervision of SIAs. In November of that year, a joint mission of the WHO Regional Office for Africa, the Regional Office for the Eastern Mediterranean and headquarters was undertaken to work with the country IV

40 For details on containment or certification issues, see www.polioeradication.org.

Communicable disease epidemiological profile 150 CENTRAL AFRICAN REPUBLIC AND CHAD danger of wild poliovirus being exported to areas in the region. region. the in to areas exported being poliovirus of wild danger the greater the countries, these in transmission interrupt to The longertakes it Pakistan. and Nigeria India, Afghanistan, in areas endemic remaining the in tion of eradica pace the regarding high very is concern International Pakistan. and Nigeria India, –Afghanistan, on countries four now depends polio eradicating in success global that advised has forEradication Polio Committee The Advisory globally. eradication of polio achievement to the risk aconstant poses areas endemic in poliovirus of wild transmission ongoing importation, following areas polio-free in outbreaks controlling in progress Despite areas. polio-free into poliovirus of wild However, follow importation region. of polio outbreaks the from poliomyelitis eradicating towards made been has progress Substantial distribution Geographical access. of difficulty and security of lack staff, of international of evacuation result a as compromised may be SNIDs and NIDs Planned immunization. routine and surveillance of polio quality may the reduce circumstances Current monitoring. and support technical enhanced with SIAs high-quality of five rounds at least conduct will Chad that envisaged it is involvement. For 2008, personal his urging President to the wrote Region African of the Director Regional the Furthermore, surveillance. and improve to quality SIA interventions key covering 6-month plan a to define Communicable disease epidemiological profile epidemiological disease Communicable circulation. poliovirus of undetected risk the and services, immunization to routine access limited in results services health to access Poor Overcrowding population. to non-immune infected from transmission facilitates movement Population Risk factors for increased burden a2-month period. within occurs adjacent districts or in adistrict within cases of AFP new number reported the in a rapid increase when suspected maybe An outbreak investigated. and notified be must case AFP Any thresholdAlert season. rainy the during increases transmission of intensity The Seasonality is important in promoting transmission. promoting in important is - 151

Lack of safe water and poor sanitation. As the disease is spread by the faecal– oral route, lack of water, and poor hygiene and sanitation promote transmission.

Prevention and control measures Case management Management of the acute phase of paralytic poliomyelitis is supportive and symptomatic:

bed rest; close monitoring of respiration; respiratory support in case of respiratory failure or pooling of pharyngeal secretions; moist hot-packs for muscle pain and spasms; passive physical therapy to stimulate muscles and prevent contractures; antispasmodic drugs; frequent turning to prevent bedsores.

If hospitalization is required, the patient should be isolated, particularly avoiding contact with children. Safe disposal of discharge and faeces, disinfection of any POLIOMYELITIS soiled articles and immediate reporting of further cases are essential. Two types of poliovirus vaccine are available: I 1. Oral poliovirus vaccine (OPV): OPV is an oral vaccine based on live attenuated strains of all three virus types (tOPV) or one specific virus type (mOPV). It is easily administered by health workers or volunteers, induces a good humoral (antibody) and mucosal (intestinal) immune response and is considerably cheaper than inactivated poliovirus vaccine (IPV). OPV is the only vaccine of II choice for poliomyelitis eradication because it achieves much better mucosal immunity than IPV while limiting dissemination of wild poliovirus in the community. Polio supplementary immunization activities were planned in CAR and Chad during 2008. III 2. Inactivated poliovirus vaccine (IPV): IPV may be given only by intramuscular injection and requires trained health workers. It elicits an excellent antibody response but only minimal intestinal mucosal response; it is much more expensive than OPV. All countries in the subregion have a routine immunization IV policy that requires three doses of OPV. However, supplementary immunization activities are also conducted in the country in order to increase immunization

Communicable disease epidemiological profile 152 CENTRAL AFRICAN REPUBLIC AND CHAD case-finding in surrounding areas. areas. surrounding in case-finding active and record reviews retrospective extensive reporting, zero and surveillance active to ensure units reporting of all monitoring intensive through enhanced be should Surveillance adjacent districts. and outbreak of the area for made the be should SIA of the on quality amajor focus planned, were already NIDs/SNIDs If requisite for polio-free certification. In case of a suspected outbreak, undertake: outbreak, suspected of a case In certification. for polio-free requisite a pre also are Such plans case. polio of a upon confirmation mop-up campaigns mount to rapidly place in procedures operating have standard should country Every Epidemiccontrol Communicable disease epidemiological profile epidemiological disease Communicable

Mop-up campaigns target a minimum of 500 000−1 million children. children. million 000−1 of 500 aminimum target Mop-up campaigns months. three next the within area to cover the planned are or SNIDs NIDs if no case wild poliovirus the of confirmation after 4weeks within ducted con be should neighbours) relevant and involved province (at the area least geographical awide OPV covering with mop-up campaigns House-to-house Intervention Investigation be vaccinated on arrival. Every AFP case must be notified and investigated. investigated. and notified be must case AFP Every on arrival. vaccinated be should months 0–59 aged children all settings, camp In used. of vaccine type the on depends two doses the between (coolerinterval season). The enteroviruses for of low transmission season the preferably during <5years, aged children to all given are OPV doses two which during mop-up campaigns, and areas) smaller but covering to NIDs similar –campaigns (SNIDs (NIDs), sub-NIDs days immunization of national consist these possible: much as as coverage a stool specimen obtained from an AFP case. AFP an from obtained specimen a stool from poliovirus wild of isolation the on based be will confirmation Outbreak

symptoms must be sent to a WHO-accredited laboratory). laboratory). sent to aWHO-accredited be must symptoms 14 of of onset days within (2 samples stool investigation virological Rapid Clinical and epidemiological investigation. epidemiological and Clinical

- - 153 RABIES

Country-specific disease burden No outbreaks have been reported to WHO from Central African Republic and Chad.

Description Infectious agent Rabies virus, a Rhabdovirus of the genus Lyssavirus.

Case definition Clinical description Paresis or paralysis, delirium, convulsions. Without medical attention, death in about 6 days, usually due to respiratory paralysis.

Clinical case definition

An acute neurological syndrome (encephalitis) dominated by forms of hyperactivity RABIES (furious rabies) or paralytic syndrome (dumb rabies) that progresses towards coma and death, usually by respiratory failure, within 7–10 days after the first symptom. Bites or scratches from a suspected animal can usually be traced in the patient’s I medical history.

Laboratory criteria One or more of the following: II detection of rabies viral antigens by direct fluorescent antibody (FA) or by ELISA in clinical specimens, preferably brain tissue (collected post mortem); detection by FA on skin biopsy (collected ante mortem); III FA positive after inoculation of brain tissue, saliva or CSF in cell culture, or after intracerebral inoculation in mice or in suckling mice; detectable rabies-neutralizing antibody titre in the serum or the CSF of an unvaccinated person; IV detection of viral nucleic acids by PCR on tissue collected post mortem or in a clinical specimen (brain tissue or skin, cornea, urine or saliva).

Communicable disease epidemiological profile 154 CENTRAL AFRICAN REPUBLIC AND CHAD Human exposure to rabies: exposure Human Human rabies: Human classification Case Communicable disease epidemiological profile epidemiological disease Communicable animals. rabies-suspect to exposed being after year each treatments postexposure receive people 10 million estimated An Asia. and of Africa areas rural in mostly 55 to be 000, estimated is by rabies caused worldwide of deaths number annual study, the to this According 2004. in of rabies burden of the reassessment a commissioned WHO health. animal and on human impact full its to assess it difficult making globe, of the areas many in scarce are on rabies data Reliable General Epidemiology species. animal other in observed have been signs of clinical before onset excretion of periods Longer disease. the of course the throughout and days) 4 (rarely over signs of for clinical before 3–7 onset days usually cats, dogsand In period Communicability from 2 to as 7 years. as long days butmaybe 10 ranges usually period incubation The Incubation period documented. been has transmission scratches introduce virus-ladeninto saliva the human body. No human-to-human (dog, fox, bat): cat, species bites or mammalian infected bite of an by the Usually Mode of transmission

laboratory-confirmed rabid animal. rabid laboratory-confirmed a abite or with ascratch) (usually contact close had who aperson Exposed: area. from) arabies-infected (or in originating animal arabies-susceptible with abite or ascratch) (usually contact close had who aperson Possibly exposed: laboratory-confirmed. is that case suspected a Confirmed: rabid animal. a of suspected plus with contact case history Probable: a suspected definition. case clinical the with compatible is that acase Suspected:

155

In the WHO African and South-East Asia regions, human mortality from endemic canine rabies was estimated to be 55 000 per year (90% confidence interval: 21 500– 90 800), with 44% of these deaths occurring in Africa. The number of deaths officially reported in most developing countries greatly underestimates the true incidence of the disease. The subregion is considered endemic for rabies. Risk of cases in humans is significant if individual cases or outbreaks of rabies are reported in dogs or other susceptible animals in the same zone. Availability of food sources for dogs and susceptible wild animals in close proximity to human populations increases the risk. Children aged 5–15 years are the group at major risk. More than 99% of all human rabies deaths occur in the developing world; although effective and economical control measures are available, the disease has not been brought under control throughout most of the affected countries. The application of effective and economical control measures is hampered by a range of economic, social and political factors. Lack of accurate data on the true public health impact of the disease is a major factor contributing to the low commitment to rabies control.

Geographical distribution RABIES The majority of rabies deaths generally occur in rural areas.

Seasonality I No seasonality reported.

Alert threshold One case in a susceptible animal species and/or human must lead to an alert. II

Risk factors for increased burden Population movement is a risk factor. III Overcrowding. An infected animal has the opportunity to bite more people; dog- population density parallels human-population density. Poor access to health services. Prompt administration of vaccine post exposure IV (plus immunoglobulin if heavy exposure) is the only way to prevent death of an infected person.

Communicable disease epidemiological profile 156 CENTRAL AFRICAN REPUBLIC AND CHAD Recommended treatments according to type of contact with suspect animal suspect with contact of to type according treatments Recommended rabies. than other infections to control administered be should drugs and antimicrobials treatment, antitetanus indicated, Where the wound. of periphery the at instillation before be applied sure) first must (in expo severe immunoglobulin necessary, it is if postponed; be should Suturing (severe) only. III for Category applied be exposures should noglobulin (see immu below). regimens Antirabies to WHO-recognized according exposures, III and II for possible Category as soon as given be should vaccine Antirabies solution of iodine. or aqueous or tincture apply ethanol water, then and plain water,and soap detergent or with contact point the of or wound flush and wash is to way torabies prevent effective The most disease. fatal invariably almost an is Rabies started. symptoms have the rabies once treatment for is specific no There Casemanagement Prevention and control measures Communicable disease epidemiological profile epidemiological disease Communicable for patients. necessary are practices nursing barrier Universal inevitable. is death disease, the develops aperson If III I II Category with saliva (i.e. licks) (i.e. saliva with skin broken on licks scratches, bleeding testing for unavailable animal or animal, wild or domestic rabid confirmed or asuspect with contact of Type

Exposures to bats bats to Exposures membrane mucous of Contamination or bites transdermal multiple or Single without abrasions or scratches Minor skin uncovered of Nibbling skin intact on Licks Minor exposure Minor exposure of Type Severe exposure Severe None diagnostic techniques. diagnostic appropriate using laboratory areliable by rabies for negative be to proven and killed humanely is animal if or 10 of days period observation an throughout healthy remains animal if treatment Stop immediately. vaccine Administer Recommended treatment Recommended techniques. diagnostic appropriate using rabies for negative be to found and killed humanely is animal if or 10 days of period observation an throughout healthy remains animal if treatment Stop immediately. vaccine and immunoglobulin rabies Administer available. is history case reliable if None, -

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Epidemic control Immediate notification if one or more suspected cases are identified. Confirm the outbreak, following WHO guidelines. Confirm diagnosis and ensure prompt management.

Prevention WHO promotes human rabies prevention through:

well-targeted postexposure treatment using modern vaccine types and, when appropriate, antirabies immunoglobulin; increased availability of safe and effective rabies vaccine; elimination of dog rabies through mass vaccination of dogs, and dog-population management.

Immunization Mass preventive vaccination in humans is generally not recommended but may be considered under certain circumstances for the age group 5–15 years. RABIES

III

Communicable disease epidemiological profile 158 CENTRAL AFRICAN REPUBLIC AND CHAD Description cause. of unknown outbreak an investigating or while diarrhoea) bloody and rics (e.g. symptoms obstet haemorrhagic with presenting of for suspicion patients index ahigh retain workers should Health outbreaks. or human animal but no reported Chad, and Republic African Central the in serology animal positive been has There Country-specific disease burden VALLEYRIFT FEVER (RVF) Communicable disease epidemiological profile epidemiological disease Communicable 2. 1. complications: have serious 2 %of cases blood. the in virus of the disappearance the as well IgG) as and (IgM detected be can antibodies the which after 4to 7days, from general in last toms symp These meningitis. with confused maybe RVF stages, first its in therefore and and vomiting nausea anorexia, photophobia,the neck, of astiffness develop may patients Some followed by aleucopenia. is Hyperleucocytosis biphasic. be fever Themay or may not and headaches. arthralgia fever, flu-like myalgia, onset, by sudden a feverish with syndrome characterized and 98% are unnoticed of cases definition case Clinical definition Case in humans). disease causes occasionally but animals, affects Bunyaviridae family the in genera the Phlebovirus is a of member virus fever (RVF) Rift Valley Infectious agent Deaths are rare. Neurological complications may appear later. may appear complications Neurological rare. are Deaths symptoms. first the 1–3 after Appears weeks coma. vertigo, ory, hallucinations, of mem Loss meningitides. and cephalgias intense form: Meningoencephalic rare. are (50% of cases). Deaths loss RVF.there visionin of is apermanent fall opticis affected, the When disc of visual causes frequent most the atrophy are optic and retinitis paramacular retinitis, Macular symptoms. of systemic onset 10–12 the from weeks within spontaneously resolve Symptoms vision. or decreased blurred report Patients symptoms. first the 1–3 after appears weeks Chorioretinitis blindness. porary tem 1% (mostaround form of frequent, RVF chorioretinitis, cases): Ocular causing zoonosis (a disease which primarily primarily which (a zoonosis disease causing genus, one of the five five onegenus, of the - - - - 159

3. Haemorrhagic icterus form: 2-4 days after the beginning of the disease, the patient presents the signs of a severe hepatitis, including jaundice and haemorrhages that may be fatal (vomiting blood, blood in the stools, purpura – an area of bleeding within the skin) or bleeding from the gums. The case-fatality ratio may be as high as 50%. Death may occur between day 3 and 6 post onset. The viraemia may last for up to 10 days.

Laboratory criteria The virus may be detected by reverse transcriptase polymerase chain reaction (RT-PCR) in the patient’s blood from day 1 to day 5, and later if the immune response is not activated. Serological tests differentiate other fevers of viral or unknown origin, and the diagnosis is facilitated by RNA analysis. The immune response to infection becomes detectable after 4–7 days, with the appearance of IgM and IgG antibodies and the disappearance of circulating virus from the bloodstream. Enzyme-linked immunosorbent assay (the ELISA or EIA methods) may demonstrate the presence of specific IgM antibodies to the virus. The virus itself or the viral genome revealed by RT-PCR may be detected in blood during the viraemia phase of illness. The virus may also be detected in postmortem tissues by a variety of techniques, including virus propagation (in cell cultures or inoculated animals), antigen detection tests and RT-PCR. RIFT VALLEY FEVER (RVF)

Community diagnosis RVF should be suspected when abnormally heavy rains are followed by the wide- I spread occurrence of abortions and mortality among newborn animals, characterized by necrotic hepatitis, and when haemorrhages and influenza-like disease are seen in people handling animals or their products. II Mode of transmission The vast majority of human infections (90%) are caused by direct or indirect contact with infected animal blood or organs (e.g. liver, spleen). These human infections are associated with handling of animal tissues during butchering or III autopsy (performed by farmers, slaughtering houses, veterinarians, etc.). The virus may also infect humans through inoculation (e.g. if the skin is broken, or through a wound from an infected knife). Some human infections are caused by mosquito bites, mainly by the bite of infected IV Aedes mosquitoes. A. mcintoshi may be infected transovarially (transmission of the virus from infected female mosquitoes to offspring via eggs) and account for

Communicable disease epidemiological profile 160 CENTRAL AFRICAN REPUBLIC AND CHAD often occurs during early clinical infection in humans. infection clinical early during occurs often and forinfection vector essential is Viraemia life. throughout virus the transmit probably mosquitoes Infected transmission. person-to-person direct is no There period Communicability fromdays. 2 to 12 varies period incubation The Incubation period documented. been has transmission No workers. person-to-person laboratory in gous flies isalso possible. The aerosol mode of transmissionhas also led toinfection by haematopha of RVF virus transmission Mechanical epidemics. to RVF in linked been have also pipens C. as such arthropods Other RVF virus. for the vectors are of mosquitoes species different Many foci. enzootic in of RVF virus maintenance Communicable disease epidemiological profile epidemiological disease Communicable livestock: among abortions wave of unexplained as a manifested first epidemic) of RVFusually is disease (animal epizootic An or cattle. sheep than susceptible less are goats while cattle, than more to be susceptible appear Sheep goats). and camels sheep, RVF (cattle, with infected may be of animals types Many humans. fect in to capacity the buthas animals effects primarily that zoonosis RVF aviral is Europe. and of Asia parts other into of expansion threat the raises Peninsula Arabian Yemen). and (Saudi the Arabia to countries expansion The neighbouring in tinent con African the outside time first for the reported RVF was 2000, September In 1997–1998. in Somalia Kenya and in occurred A major outbreak Africa. northern and sub-Saharan in of have occurred RVF Outbreaks of Kenya. Rift Valley the in Naivasha of Lake north on afarm sheep among epidemic of an investigation the during isolated infirst 1931.The was identified was virus(RVFV) fever Rift Valley General Epidemiology

sheep may be as low 10%. as as may be sheep adult among mortality whereas RVF die, with infected of lambs over 90% illness: severe to susceptibility their in differ also ages of different animals 100%; almost is ewes infected pregnant, among rate abortion the - - - 161

An epizootic may signal the start of a human epidemic:

The vast majority of human infections result from direct or indirect contact with the blood or organs of infected animals. The virus may be transmitted to humans through the handling of animal tissue during slaughtering or butchering, assisting with animal births, conducting veterinary procedures, or from the disposal of carcasses or fetuses. Certain occupational groups such as herders, farmers, slaughterhouse workers and veterinarians are therefore at higher risk of infection. The virus infects humans through inoculation, for example via a wound from an infected knife or through contact with broken skin, or through inhalation of aerosols produced during the slaughter of infected animals. The aerosol mode of transmission has also led to infection in laboratory workers. There is some evidence that humans may also become infected with RVF by ingesting the unpasteurized or uncooked milk of infected animals. Human infections have also resulted from the bites of infected mosquitoes, most commonly the Aedes mosquito. Transmission of RVF virus by hematophagous (blood-feeding) flies is also RIFT VALLEY FEVER (RVF) possible. To date, no human-to-human transmission of RVF has been documented, and no transmission of RVF to health-care workers has been reported when standard infection-control precautions have been put in place. I There has been no evidence of outbreaks of RVF in urban areas.

Seasonality II In warmer climates where insect vectors are present continuously, seasonality is usually not seen. However, epidemics may occur following exceptionally heavy rains as a result of an increase in the number of vector breeding sites and conditions. New systems that monitor variations in climatic conditions are being applied to give advance warning of impending outbreaks by signalling events III that may lead to increases in mosquito numbers. Such warnings allow authorities to implement pre-emptive public health measures to avert an impending epidemic. IV Susceptibility appears to be general in both sexes at all ages. Since infection leads to immunity, susceptible individuals in endemic areas are mainly children.

Communicable disease epidemiological profile 162 CENTRAL AFRICAN REPUBLIC AND CHAD Population movement. Risk factors for increased burden Communicable disease epidemiological profile epidemiological disease Communicable mainstay: the is more cases severe the for treatment Supportive plasma. convalescent-phase and modulators immune interferon, include consideration under treatments Other success. without Arabia Saudi in outbreak 2000 the of during cases RVF of confirmed treatment the in employed was Ribavirin disease. the fortreatment no specific is there Currently, uncommon. is disease ocular only with patients in Death appear. symptoms first the after 1–3 weeks usually is disease eye of The onset macula. the in are lesions the if of vision loss permanent with retinitis (0.5–2%) vascular develop proportion Ahigher uncommon. is meningoencephalitis only with patients in Death symptoms appear. first the 1–3 after weeks usually also is syndrome this of The onset meningoencephalitis. in result 1% of than RVF infections Less 50%. at approximately high is disease haemorrhagic developing patients for ratio forcase-fatality up to 10 The days. viraemic may remain fever syndrome RVF haemorrhagic the with Patients gums. the from bleeding and rash a purpuric developing faeces, the in blood passing blood, phenomena, vomiting haemorrhagic and petechiae jaundice, with disease, liver of severe shows patient evidence the illness, fever. of the Twoonset haemorrhagic after afatal days in to four result However,treatment. may specific infections any of 1% or less not require RVF will so and duration, of short illness febrile mild relatively of RVF are cases human Most illness. febrile amild as characterized usually is humans among Disease Casemanagement Prevention and control measures disease. the die of to arelikely more malnourished The shortages. Food measures. control of outbreak implementation and management appropriate case for essential is services to medical Prompt access services. health to access Poor transmission. for increased factor arisk constitute to vectors exposure Overcrowding. areas. to non-affected of spread infection and expansion the

rehydration, electrolytic balance, intensive care; intensive balance, electrolytic rehydration, platelets; cells, red components, volume and blood replacement of the Conditions favouring close contact with infected animals and and animals infected with contact close favouring Conditions During outbreaks, livestock movement to may livestock contribute outbreaks, During 163

use of antibiotics drugs (to avoid secondary infections); use of antimalarial drugs if needed (coinfections); analgesic drugs.

Although person-to-person transmission has not been documented, standard infection-control practices should be implemented to avoid possible secondary infections when managing patients with the haemorrhagic form of the disease. RVF virus should be considered as a bloodborne pathogen. Contact with the patient’s lesions and body fluids should be minimized using standard infection- control practices including:

restriction of access to patient wards; use of personal protective equipment; safe disposal of waste; disinfection of all non-disposable supplies and equipment; safe burial practices.

Immunization

A formalin-inactivated vaccine named TSI-GSD-200 (3 injections) has been RIFT VALLEY FEVER (RVF) developed by the Salk Institute for human use. It is shown to be safe and immunogenic in human studies. Testing of this vaccine in 598 at-risk laboratory personnel in 1986–1997 showed only minor side-effects and good long-term immunity at I 12-year follow-up. However, this vaccine is not licensed and is not commercially available. A single-dose human live attenuated vaccine, named MP-12, is currently under- going trials. An open-label, single-dose, phase II study is ongoing to assess the II safety, immunogenicity, and genetic stability of RVF MP-12 vaccine in humans, but it is not approved for human use. Other candidate vaccines are under investigation. Killed RVF virus (RVFV) vaccines and live-attenuated RVFV vaccines for animals (veterinary use) are available, but they may cause birth defects and III abortions in pregnant animals (see below under Prevention and control for use).

Prevention and control Controlling RVF in animals IV Outbreaks of RVF in animals may be prevented by a sustained programme of animal vaccination. Both modified live attenuated virus and inactivated virus

Communicable disease epidemiological profile 164 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable reduction risk and education health Public

Public health messages for risk reduction should focus on: focus should reduction for risk messages health Public deaths. and infection way human to reduce only the is prevent bites, mosquito to take can individuals measures protective the as well as of RVF infection factors risk the of awareness raising vaccine, human effective an and treatment specific of absence the In infection. virus for factor risk RVF significant most the as identified been has aerosols, via or directly either fluids, body their with particularly animals, of RVF, with outbreak contact an close During authorities. health public human and for veterinary warning early providing in essential is cases new to detect system surveillance health animal active an of establishment the cases, human precede animals of RVF in outbreaks As areas. to uninfected infected from virus of the expansion the slowing in effective may be movement the of livestock or banning Restricting amplified. be will outbreak the and herd, the among transmitted be will virus the illness), of signs obvious not displaying yet (although viraemic and infected already herd are the in animals some of the If syringes. and of needles reuse the and vials of multidose use the through virus the may,ers transmit inadvertently, work animal-health campaigns, animal-vaccination mass During outbreak. should vaccination animal occurred, has outbreak an Once prevented. to be is ootic epiz an if outbreak implemented prior to an be must immunization Animal endemic areas. areas. endemic may prove which problematic in order protection to provide in required are multipledoses but side-effect, this nothave does vaccine virus inactivated The animals. to pregnant given if abortion spontaneous in may result use in currently is that vaccine but the long-term to provide immunity, required is vaccine live one of the dose Only use. for veterinary developed have been vaccines

sick animals or their tissues or when slaughtering animals. animals. or slaughtering when tissues or their animals sick handling when taken care and worn be should clothing protective priate appro other Gloves and practices. slaughtering and husbandry animal of unsafe a result as transmission of animal-to-human risk the Reducing cooked before eating. cooked thoroughly be should milk) and meat (blood, products animal all regions, epizootic In tissue. or animal raw milk blood, of fresh consumption safe un the from arising transmission of animal-to-human risk the Reducing not be implemented because there is a high risk of intensifying the the of intensifying risk ahigh is there implemented because be - - - - 165

The importance of personal and community protection against mosquito bites through the use of impregnated mosquito nets, personal insect repellent if available, wearing light-coloured clothing (long-sleeved shirts and trousers) and avoiding outdoor activity at peak biting times of the vector species.

Infection control in health-care settings Although no human-to-human transmission of RVF has been demonstrated, there is still a theoretical risk of transmission of the virus from infected patients to health-care workers through contact with infected blood or tissues. Health- care workers caring for patients with suspected or confirmed RVF should implement standard precautions when handling specimens from patients. Standard precautions define the work practices that are required to ensure a basic level of infection control. Standard precautions are recommended in the care and treatment of all patients regardless of their perceived or confirmed infectious status. They cover the handling of blood (including dried blood), all other body fluids, secretions and excretions (excluding sweat), regardless of whether they contain visible blood, and contact with non-intact skin and mucous membranes.41 RIFT VALLEY FEVER (RVF) As noted above, laboratory workers are also at risk. Samples taken from suspected human and animal cases of RVF for diagnosis should be handled by trained staff and processed in suitably equipped laboratories. I

Vector control Other ways in which to control the spread of RVF involve control of the vector and protection against bites. II Larviciding measures at mosquito breeding sites are the most effective form of vector control if breeding sites can be clearly identified and are limited in size and extent. During periods of flooding, however, the number and extent of breeding sites is usually too high for larviciding measures to be feasible. III

The risk of transmission from infected blood or tissues exists for people working with infected animals or for individuals during an outbreak: IV 41 A WHO aide–memoire on standard precautions in health care is available at http://www.who.int/csr/ resources/publications/standardprecautions/en/index.html.

Communicable disease epidemiological profile 166 CENTRAL AFRICAN REPUBLIC AND CHAD (OIE). épizooties des international Office as known also (FAO) Organisation, Nations Health World the and Animal United of the Organization Agriculture and Food WHO, the authorities, local to notified be must animals and humans in cases/epidemics suspect Importantly, Communicable disease epidemiological profile epidemiological disease Communicable 3. 2. 1. controlthe of epidemics: in RVF essential are elements key The following Epidemiccontrol

dled by trained staff and processed in suitably equipped laboratories. laboratories. equipped suitably in and processed staff by trained dled han of be RVF should cases animal and human suspected from for diagnosis taken samples so at risk, are samples collecting those workers and laboratory patients; from specimens processing and taking when precautions employshould standard RVF confirmed or suspected with patients after workers looking health-care tissues; or their mals ani sick handling when taken care and worn, be should clothing protective appropriate other aprons and gowns, boots, masks, surgical goggles, gloves, and restrict practices that promote transmission in the community such as: as: such community the in promote transmission that practices restrict and public the to inform programmes education health and mobilization Social authorities. health human and animal between interventions on coordination efficient and Effective operations. control outbreak in involved partners by all recognized is that response for outbreak mechanism A coordination

any animal fluids; animal any with contact after immediately or soap disinfectant with hands washing or fetuses; animals dead burying placenta), slaughtering, and (fetus birth ting assis when particularly animals, or sick dead bags) handling when plastic e.g. contact, to avoid direct (or device other masks any and gloves wearing suspected appropriate protection; RVF without with fetuses) of infection their (and animals manipulating or slaughtering avoiding animals; of sick dead or fluids body animal with contact direct avoiding controlling animal slaughtering activities at home and in facilities; at in home and activities slaughtering animal controlling meats; animal of dead consumption avoiding seasons; festive lead-up to community the in especially hand-hygiene, and practices slaughter and husbandry animal safe ensuring

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early reporting of suspected cases in humans and animals; using personal protective equipment when handling patients and articles belonging to patients with RVF; seeking early treatment for human infections; avoiding risky funeral practices. 4. Safe and humane case management, including standard infection control practices and appropriate funeral practices. 5. Vigilant surveillance, standardized epidemiological practices (serological surveys to identify infected animals and affected districts) and appropriate laboratory services. 6. Health and veterinary workers in RVF-prone areas should receive advance training in the use of standard infection-control precautions for avoidance of mechanical infections. 7. Animal health measures to limit the epizootic: restrict movement of animals from enzootic areas to clean areas; do not vaccinate in epizootic areas; if climatic conditions are signalling a high risk for an RVF epidemic, vete- RIFT VALLEY FEVER (RVF) rinary services might vaccinate in at-risk zones to avert an impending epidemic. 8. Implement international administrative measures, as required: I enforce international agreements designed to prevent transfer of mosquitoes by ships, airplanes and land transport; OIE and FAO may restrict the trade of animals from an affected country to an RVF-free country. II 9. Provision of good logistics and security.

III

Communicable disease epidemiological profile 168 CENTRAL AFRICAN REPUBLIC AND CHAD out the country. out the through widespread is mansoni of S. Transmission hosts. snail to the favourable environment an represent waters or slow-flowing border, Chad the wherestagnant along plains marshy the in intense particularly is haematobium of S. Transmission rivers). Barya Nana and Ouham Gribingui, Manovo, Oulou, Bahr river the (along Chari the of basin the upper in as aswell affluents, its and river Oubangui of the banks on found the is and widespread less is somiasis schisto Urinary country. the throughout reported is schistosomiasis Intestinal Central African Republic intercalatum S. ( urinary of schistosomiasis, types Both Country-specific disease burden SCHISTOSOMIASIS(BILHARZIASIS) Communicable disease epidemiological profile epidemiological disease Communicable worms fluke blood are All schistosomiasis). (agent mansoni of intestinal tosoma Schis schistosomiasis); (agent of haematobium urinary Schistosoma Helminths: Infectious agent Description flood-plain. annual their in remain which pools the in and tributaries, in branches, minor their in high is transmission rivers, Chari and Logone of the channel main the not in found are hosts snail While massif. Ouaddaï of the springs to the and south-west of the watercourses to permanent limited mansoni of S. transmission while country, of the half southern the in bodies water- or permanent temporary all in occurs haematobium of S. Transmission schistosomiasis. for urinary lower than usually are intensity and prevalence basins; river Chari and Logone the in mainly occurs schistosomiasis Intestinal country. of the west the in region, densely-populated most the basins, river Chari and Logone the in and zone Sahelian the in highest are the northern that part is sparsely populated); prevalence and intensity of infection of exception the (with country the present throughout is schistosomiasis Urinary Chad ), are endemic in the Central African Republic and Chad. and Republic African Central the in endemic ), are S. haematobium S. ) and intestinal ( intestinal ) and S. mansoni, S. is is - - -

169 belonging to the class Trematoda. Intestinal schistosomiasis caused by Schistosoma intercalatum may be endemic in the tropical rain forest areas of DRC and Chad.42

Case definition Urinary schistosomiasis Endemic areas (moderate or high prevalence): Suspected: not applicable. Probable: not applicable. Confirmed: a person with visible haematuria; or positive reagent strip for haematuria; or S. haematobium eggs in urine (microscopy).

Non-endemic areas and areas of low prevalence: Suspected: a person with visible haematuria; or positive reagent strip for haematuria; and possible contact with infective water. Probable: not applicable. Confirmed: a person with S. haematobium eggs in urine (microscopy).

Intestinal schistosomiasis

Endemic areas (moderate or high prevalence): SCHISTOSOMIASIS(BILHARZIASIS) Suspected: a person with nonspecific abdominal symptoms, blood in stool, hepato(spleno)megaly. Probable: a person who meets the criteria for presumptive treatment, accor- I ding to the locally-applicable diagnostic algorithms. Confirmed: a person with eggs of S. mansoni in stools (microscopy).

Non-endemic areas and areas of low prevalence: II Suspected: a person with nonspecific abdominal symptoms, blood in stools, hepatosplenomegaly and possible contact with infective water. Probable: not applicable. Confirmed: a person with eggs of S. mansoni in stools (microscopy). III Mode of transmission The disease is water-related, and occurs when the human skin is penetrated by the schistosome larvae (cercariae). Patients with schistosomiasis discharge the IV

42 http://www.who.int/wormcontrol/databank/Chad_ncp2.pdf .

Communicable disease epidemiological profile 170 CENTRAL AFRICAN REPUBLIC AND CHAD may result in increased local schistosomiasis transmission. schistosomiasis local increased in may result areas endemic in projects dam and irrigation of Construction fishing). and culture agri in engaged people among (mainly water in or wading working swimming, is person the while usually skin, human penetrate and snail the emerge from Biomphalaria ( hosts snail suitable penetrate that (miracidia) larvae first-stage haematobium S. ally Incubation period ( urine their in eggs schistosome Communicable disease epidemiological profile epidemiological disease Communicable tend to occur: cases general, In distribution Geographical fundamental. therefore is distribution pathogen of mapping The appropriate. may be for both treatment coordinated helminthiasis, soil-transmitted with coendemic may be schistosomiasis As moved to Kenya. populations Somali infected when 2007 in demonstrated as sources, water around congregate also who populations refugee and IDPin amplified and mirrored may be of disease Suchpatterns sources. water around concentrate populations where occurs transmission intense The most General Epidemiology infection. after 10 years than mayfrom be This by patients. 10–12 to As long discharged more are weeks eggs as period Communicability

in settlements near perennial or semi-permanent ponds or lakes. or lakes. ponds or semi-permanent perennial near settlements in changes; by seasonal caused formations lake recurrent in areas; irrigated in settlements in valleys; major river along manifestations. illness chronic years: From to several 3months infection). haematobium S. in absent completely almost fever; (Katayama reaction febrile acute weeks: 2–8 Within penetration. site of cercarial at the dermatitis localized 4days: Within spp.) and develop into final-stage larvae (cercariae). The cercariae cercariae The (cercariae). larvae spp.) final-stage into develop and ). When the eggs reach a body of fresh water, they liberate liberate water, of they fresh abody reach eggs the ). When S. haematobium S. ) or faeces ( ) or faeces S. mansoni S. Bulinus , occasion spp. and spp. and - - 171

Seasonality Overall, transmission of schistosomiasis occurs throughout the year. Transmission in semi-permanent ponds or lakes is linked to the rainy season (June–September). In certain conditions, dry periods tend to increase transmission of the disease as a result of higher cercarial densities in bodies of water and of drying of wells, with consequent increased use of unsafe water.

Risk factors for increased burden Population movement may lead to the introduction of S. mansoni and/or S. haematobium in areas previously free or endemic for only one of the species. Overcrowding. Higher human densities lead to increased discharge of schistosome eggs in bodies of water and therefore to an increased chance of snails being penetrated and colonized by miracidia. Poor access to health services. Regular treatment of cases and preventive chemotherapy have been proven effective in reducing egg discharge, thus limiting introduction of Schistosoma spp. into schistosome-free areas. Reduced egg discharge also prevents late-stage complications of schistosomiasis in infected individuals. SCHISTOSOMIASIS(BILHARZIASIS) Food shortages. Malnutrition and schistosomiasis have a synergic role in causing iron-deficiency anaemia. Lack of safe water and poor sanitation. The use of surface water infested by cer- I cariae and contamination of water by urination/defecation are prerequisites for the transmission of schistosomiasis.

Prevention and control measures II Case management Praziquantel is the drug of choice against all schistosome parasites. A single oral dose of 40 mg/kg is generally sufficient to produce cure rates of 80–90% and dramatic reductions in the average number of eggs excreted. Praziquantel treatment III for one person requires, on average, 3 tablets of 600 mg in one dose. The cost of a tablet is now less than US$ 0.10, bringing the total drug cost of a treatment to about US$ 0.30. Drug costs decrease when the entire population is included in prevention programmes. A dose pole (for calculating dosage according to height) IV is available to facilitate the delivery of praziquantel in schools or in community- based programmes.

Communicable disease epidemiological profile 172 CENTRAL AFRICAN REPUBLIC AND CHAD ventions are: inter recommended to preventive chemotherapy, other addition In programmes. control in before used it is tested be should drug of the quality the so, if market; local on the available may be Praziquantel 2004. in completed successfully was programme –apilot praziquantel with school-deworming to include grammes pro distribution food country its expanding is WorldNations Programme Food The United of localities. number alimited implemented in initially was treatment Community workers. health school and cooperatives workers, health community by of praziquantel distribution the with concerned workbe should Programme infections. of concomitant severity the ing increas role it in plays the as well as individuals of infected status health general the on disease this of effect the given interventions priority are schistosomiasis of control and management Case age. women of and childbearing for children generally administration, drug mass coordinated as occurs of helminths Control Prevention Communicable disease epidemiological profile epidemiological disease Communicable 43

Treatment of snail-breeding sites with molluscicide molluscicide with sites Treatment of snail-breeding management). environmental and practices, tural agricul and irrigation (through contact snail and habitats of snail Reduction of excreta. proper disposal and water of safe use behaviour, care-seeking to promote education early Health hosts. snail containing of water bodies reaching from eggs to prevent viable urine and of faeces disposal Proper water. infective with tocontact reduce sources water safe of alternative, Creation (see below). categories prevalence to community according ment populations of endemic treat regular and surveys) school primary (through diagnosis Community For documents and publications on schistosomiasis, see http://www.who.int/wormcontrol/en/. see schistosomiasis, on publications and documents For 43 - - - - - 173

Recommended treatment strategy for schistosomiasis in preventive chemotherapy

Category Prevalence among Action to be taken school-age children

High-risk community > 50% by parasitological Treat all school-age Also treat adults methods (intestinal and children (enrolled and not considered to be at risk urinary tract schisto enrolled) once a year (from special groups to somiasis); or > 30% by entire communities living questionnaire for visible in endemic areas). haematuria (urinary schistosomiasis)

Moderate-risk community > 10% but < 50% by Treat all school-age Also treat adults parasitological methods children (enrolled and not considered to be at risk (intestinal and urinary enrolled) once every 2 years (special risk groups only). schistosomiasis); or < 30% by questionnaire for visible haematuria (urinary schistosomiasis)

Low-risk community < 10% by parasitological Treat all school-age Praziquantel should be methods (intestinal and children (enrolled and not available in dispensaries urinary schistosomiasis) enrolled) twice during and clinics for treatment of

their primary schooling suspected cases. SCHISTOSOMIASIS(BILHARZIASIS) (e.g. once on entry and once on exit)

Source: Preventive chemotherapy in human helminthiasis: coordinated use of anthelminthic drugs in control interventions. A manual for health professionals and programme managers. Geneva, World Health Organization, 2006. I

III

Communicable disease epidemiological profile 174 CENTRAL AFRICAN REPUBLIC AND CHAD trichiura or T. trichiura lumbricoides A. of ova to the unfavourable are west and north the in experienced temperatures extreme The country. of the east and south the of 32.7% in to have aprevalence Chad zones. tropical the in country of the north-west and north the in tribution dis geographical showtomarked expected be may butinfection sparse, are Data Central African Republic Country-specific disease burden INFECTION,TRICHURIASIS)HOOKWORM SOIL-TRANSMITTED HELMINTHIASES (ASCARIASIS, Communicable disease epidemiological profile epidemiological disease Communicable 44 infection Hookworm Ascariasis definition Case lumbricoides Ascaris Helminths: Infectious agent Description 2002. in completed was children of school survey Anationwide country). of the zones tropical and (the Sudanian south-east and east the in distribution geographical shows amarked Infection

625-630. 7(7): 2002, Health, International and Medicine Tropical Chad. in schoolchildren of Health al. Met Beasley scopic examination). stools in (micro eggs andof hookworm presence case suspected Confirmed: cause. obvious no other is there for which anaemia severe Suspected: (microscopic examination). stools in eggs nose), lumbricoides of or A. presence and (anus, mouth lumbricoides of A. andpassage case suspected Confirmed: worms. of passing history and symptoms or respiratory abdominal Suspected: . . 44 , hookworm ( , hookworm Hookworm ( Hookworm Necator americanus Necator americanus ), ), ) was found found ) was Trichuris Trichuris - - - 175

Trichuriasis Suspected: bloody, mucoid stools. Confirmed: suspected case and presence of T. trichiura eggs in stools.

Mode of transmission Ingestion of eggs, mainly as a contaminant of food: A. lumbricoides and T. trichiura. Active penetration of the skin by larvae in the soil (hookworm).

Incubation period 4–8 weeks for A. lumbricoides. From a few weeks to many months for hookworm disease. Unspecified for T. trichiura.

Communicability period

A. lumbricoides eggs appear in the faeces 45–75 days after ingestion and become infective in soil after 14–21 days. They may remain viable in soil for years. Infected people may contaminate soil as long as mature fertilized female worms live in the intestine (lifespan of adult worms can be 12–24 months). SOIL-TRANSMITTED HELMINTHIASESSOIL-TRANSMITTED (ASCARIASIS, HOOKWORM INFECTION, TRICHURIASIS) Hookworm eggs appear in the faeces 6–7 weeks after infection. As larvae, they become infective in soil after 7–10 days and may remain infective for several weeks. Infected people may contaminate soil for several years. T. trichiura eggs appear in the faeces 70–90 days after ingestion and become infec- I tive in soil after 10–14 days. Infected people may contaminate soil for several years.

Epidemiology II General STH infection is usually endemic, with little likelihood of rapid changes in incidence. Surveys identify areas of particularly high endemicity where mass treatment is warranted. Soil-transmitted helminthiasis may be coendemic with schistosomiasis, III so that coordinated treatment for both may be appropriate. STH infections can be controlled with low-cost, highly effective interventions that markedly improve the quality of life of affected populations.45 IV 45 http://www.who.int/wormcontrol/databank/en/; http://www.who.int/wormcontrol/documents/maps/en/ car.pdf; http://www.who.int/wormcontrol/documents/maps/en/chad.pdf.

Communicable disease epidemiological profile 176 CENTRAL AFRICAN REPUBLIC AND CHAD Risk factors for increased burden (April–May). season dry end of the at the is rate lowest transmission (September–October). The season rainy end of the at the usually is transmission or T. trichiura lumbricoides of ova A. to the unfavourable being tures tempera extreme with parameters, environmental by influenced is Distribution Seasonality countries. for these scarce remain distribution on geographical data Epidemiological distribution Geographical Communicable disease epidemiological profile epidemiological disease Communicable on preventive chemotherapy. guidelines to WHO according groups high-risk other and children of school-age deworming for annual call would areas Highly-endemic Control fundamental. is distribution of pathogen mapping the administration, drug mass coordinated as occurs of control helminthiasis As Prevention Prevention and control measures factor. important most the is facilities sanitation using effectively people of The proportion sanitation. poor and water safe of Lack deficiency. A vitamin and anaemia iron-deficiency causing role in have asynergic infections STH and Malnutrition shortages. Food (preventive chemotherapy). viduals indi infected in infections development due to STH preventing of morbidity in effective highly to be shown been has treatment However, rates. mission regular trans overall and reducing cycle transmission the on breaking effect alimited has communities endemic of entire treatment Regular services. health to access Poor of faeces. disposal of unsafe Overcrowding. days). (at 45–50 least themselves infective become and patient infected by an discharged to be for eggs needed that than shorter of time for place aperiod same the in remain people if factor not arisk is It sanitation. to insufficient linked exclusively is Risk movement. Population Risk is exclusively linked to the number of people defecating and and of defecating people number to the linked exclusively is Risk . The peak of peak . The - - - 177

Control of STH infections can play a major role in reducing the burden of communicable disease borne by populations in emergency situations. Moreover, given its simplicity and feasibility, control of STH infections may represent a starting point for the reconstruction of health-care systems in countries affected by emergencies.

Case management All STH compete with the host for nutrients, causing malabsorption of fats, pro- teins, carbohydrates and vitamins, and directly contributing to malnutrition. They may also cause growth retardation. A. lumbricoides infestation exacerbates vitamin A deficiency. Elimination of ascarids may result in rapid clinical improvement in night blindness and dryness around the eye. Hookworm infestation is strongly associated with chronic anaemia. Significant inverse correlations between intensity of worm infestation and haemoglobin level have been demonstrated. Heavy T. trichiura infestation may cause diarrhoea and severe malabsorption. STH may be controlled with very cheap interventions. The average cost in a school distribution campaign (including drugs, distribution and monitoring activities) is approximately US$ 0.10–0.15 per child.

For treatment, the following four drugs are recommended by WHO and may be HELMINTHIASESSOIL-TRANSMITTED (ASCARIASIS, HOOKWORM INFECTION, TRICHURIASIS) safely administered to children past the first year of life:

Albendazole 400 mg single dose (200 mg in children aged 1–2 years); or I Mebendazole 500 mg single dose; or Levamisole 2.5 mg/kg single dose; or Pyrantel 10 mg/kg single dose. II Levamisole and pyrantel are less commonly used because they are more difficult to administer.

Notes III 1. These drugs must not be given during the first trimester of pregnancy. 2. Where mass treatment with albendazole for filariasis is envisaged, chemotherapy of intestinal helminths will take place as part of antifilarial chemoprophylaxis. 3. Iron supplementation is also recommended in communities with high preva- IV lence of iron-deficiency anaemia (such as those where hookworm disease is highly endemic).

Communicable disease epidemiological profile 178 CENTRAL AFRICAN REPUBLIC AND CHAD Recommended treatment strategy for helminthiases soil-transmitted Communicable disease epidemiological profile epidemiological disease Communicable b a ventions. inter control in drugs anthelminthic of use coordinated helminthiasis: human in chemotherapy Preventive Source: High-risk community High-risk Low-risk community Low-risk Category frequency of treatment would be every 4 months. 4 months. every be would treatment of frequency appropriate the case, In this be added. might intervention distribution drug a third available, are If resources basis. case-by-case on a with dealt be should individuals Affected recommended. not are interventions chemotherapy preventive large-scale 20%, than less is STH any of prevalence When A manual Afor manual professionals health andWorld Geneva, managers. programme 2006. Organization, Health > 50% > 50% > 20% and <50% and > 20% school-age children school-age among infection STH any of Prevalence a enrolled) twice each year each twice enrolled) not and (enrolled children school-age all Treat enrolled) once each year each once enrolled) not and (enrolled children school-age all Treat Action to be taken be to Action b Also treat: Also mothers; lactating and trimesters 3rd and 2nd the in women pregnant including age, tea-pickers and miners). and tea-pickers (e.g. occupations certain mothers; lactating and trimesters 3rd and 2nd the in women pregnant including age, miners). and tea-pickers (e.g. occupations certain

women of childbearing childbearing of women children; Preschool adults at high risk in in risk high at adults childbearing of women children; Preschool in risk high at adults - 179 TETANUS

Country-specific disease burden Central African Republic and Chad are among the countries where MNT is still a public health problem and they are also among 16 countries where less than 50% of districts have eliminated MNT. Elimination is defined by WHO as fewer than 1 case of neonatal tetanus per 1000 live births in all districts.

Central African Republic A total of 68 cases of tetanus was reported for 2007, all of which were reported as neonatal.46

Chad A total of 100 cases of tetanus was reported for 2007, all of which were reported as neonatal.47

Description TETANUS Infectious agent The bacterium Clostridium tetani. I Case definition48 Suspected case of neonatal tetanus: any neonatal death between 3 and 28 days of age in which the cause of death is unknown; or II any neonate reported as having suffered from neonatal tetanus between 3 and 28 days of age and not investigated

Confirmed case of neonatal tetanus: any neonate with normal ability to suck III and cry during the first 2 days of life; and who

46 http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencette.htm. 47 http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencette.htm. 48 Source; WHO-recommended standards for surveillance of selected vaccine preventable diseases. IV (WHO/V&B/03.01) (http://www.who.int/immunization/documents/WHO_VB_03.01/en/index.html; http://www.who.int/immunization/documents/WHO_VB_03.01/en/index.html)

Communicable disease epidemiological profile 180 CENTRAL AFRICAN REPUBLIC AND CHAD umbilical stump after delivery). after stump umbilical on the materials of contaminated application the or through delivery, during cord the to cut instrument unclean of an use the cord (e.g. through umbilical the via of spores introduction the through occurs usually tetanus Neonatal attention. for medical trivial too considered have followed wounds Cases circumcision. and includeabortions that procedures surgical after Or tissue. or soil-damaged dust faeces, spore-contaminated with wound apuncture through body the into duced intro are spores the when occurs humans). (including Infection of animals tracts gastrointestinal the in and of soil constituents as worldwide occur spores tetani C. Mode of transmission Communicable disease epidemiological profile epidemiological disease Communicable 49 Globally: General Epidemiology transmission. person-to-person No direct period Communicability 10 average months, days. one to several day 3–21 range days, Incubation period confirmed. confirmed. be considered to are by physicians reported cases NT laboratory-confirmation. Note

http://www.who.int/immunization_monitoring/diseases/Tetanus_coverage.jpg . http://www.who.int/immunization_monitoring/diseases/Tetanus_coverage.jpg including in the African region. region. African the in including underreported vastly are (MNT) tetanus neonatal and of maternal Cases All countries aim at “ aim countries All risen. has DTP3 coverage of as declined has tetanus incidence of reported annual The . The basis for case classification is entirely clinical and does not depend on not does and clinical is entirely classification case for basis . The

becomes stiff or has spasms (i.e. jerking of the muscles). of jerking spasms (i.e. has or stiff becomes and normally; suck cannot of age, days 28 3and between 49 eliminating MNT as a public health problem. health apublic as ” MNT

- 181

WHO estimates that globally about 160 000 deaths occur every year as a result of tetanus, of which 128 000 were newborns (2004 estimates). Most of these neonatal tetanus (NT) deaths occur in less than 50 countries in Asia and Africa.

Geographical distribution Worldwide.

Seasonality Universal.

Risk factors for increased burden Poor access to health services means:

increased likelihood for poor wound management and treatment; decreased likelihood for protection through immunization; increased possibility of risk-prone behaviour surrounding childbirth (thus increasing risk for neonatal tetanus). TETANUS Prevention and control measures Case management See Annex 3, Wounds and injuries. I

Epidemic control Outbreaks are rare, but when they occur a thorough case-investigation and search should be undertaken for a common source, e.g. repeated use of needles for injec- II tions, unhygienic medical and/or delivery procedures, low vaccination coverage.

Prevention Education of the public on the necessity of immunization. III Universal active immunization. Prophylactic wound management.

Prevention of maternal and neonatal tetanus requires maternal immunization with IV tetanus toxoid vaccine, and use of hygienic delivery practices (e.g. assistance by a trained attendant, delivery in a health facility, change of harmful traditional practices).

Communicable disease epidemiological profile 182 CENTRAL AFRICAN REPUBLIC AND CHAD TB burden, Central African Republic, 2006 estimates 2006 Republic, African Central burden, TB (67%) HIV. impoverished with the among and/or those vulnerability extreme with population, entire the affects disease The CAR. for disease of burden a significant represents TB globally, countries highest-burden 22 the among not listed Although Central African Republic Country-specific disease burden TUBERCULOSIS Communicable disease epidemiological profile epidemiological disease Communicable Source: estimates 2005 Chad, burden, TB Chad Source: (WHO/HTM/TB/2008.393). (WHO/HTM/TB/2008.393). Proportion of new TB cases that are multidrug-resistant (2004) multidrug-resistant are that cases TB new of Proportion (15–49 years) patients TB adult in HIV of Prevalence year) per population 000 100 per (deaths Mortality year) (per rate incidence in Trend > female year, male per population 000 100 per cases (new Incidence population) 000 100 per (allcases Prevalence MDR with cases TB New (15–49 years) patients TB adult in HIV of Prevalence year) per population 000 100 per (deaths Mortality year, 2004–2005) (per rate incidence in Trend >female male year), per population 000 100 per cases (new Incidence year) per population 000 100 per (allcases Prevalence Global tuberculosis control: surveillance, planning, financing. financing. planning, surveillance, control: tuberculosis Global financing. planning, surveillance, control: tuberculosis Global Geneva, World Health Organization, 2008 2008 Organization, World Health Geneva, 2008 Organization, World Health Geneva, 1.6% 18% 76 -0.1% 299 570 1.1% data No 80 -0.1% 345 528 183 Description Infectious agent The bacterium Mycobacterium tuberculosis. This complex includes M. tuberculosis and M. africanum primarily from humans, and M. bovis primarily from cattle. More recently, M. canettii and M. microti have been incorporated in this complex.

Case definition Clinical description The most important symptom in the selection of a tuberculosis (TB) suspect is productive cough of long duration (> 2 weeks or in accordance with current national tuberculosis control programme (NTCP) directives). Patients with TB often have other symptoms such as: haemoptysis significant weight loss chest pain breathlessness fever/night sweats TUBERCULOSIS tiredness loss of appetite.

In camp settings, it is the priority of the health services to detect the sources of I infection by sputum microscopy, and to cure them. Pulmonary TB patients with sputum-positive microscopy are the main source of TB infection.

Case classification II Suspect: any person who presents with symptoms or signs suggestive of TB, in particular cough of long duration (> 2 weeks or in accordance with current NTCP directives). Case:* a patient in whom TB has been bacteriologically confirmed or diagnosed III by a clinician. Note. Any person given anti-TB treatment should be recorded as a case. A “trial” TB treatment should not be given as a method for diagnosis. Definite case:* a patient who is culture-positive for the M. tuberculosis complex. In countries where culture is not routinely available, a patient with one or IV more sputum smears positive for acid-fast bacilli (AFB) is also considered a “definite” case.

Communicable disease epidemiological profile 184 CENTRAL AFRICAN REPUBLIC AND CHAD mg/kg/day for (5 6months). to them provided mg/kg/day be should (IPT) preventive therapy insoniazid TB, no active is there shows that <5years aged contacts of TB screening the If HIV-positive persons. as such conditions underlying with people and dren to chil given be should for screening TB priority the contacts, TB Among above. described procedures the using for TB, screened of long be duration) should cough (e.g. for suspicion TB productive symptoms suggestive with contacts TB Close shelter. same the in sleeping or individuals members family either cases, positive smear- of known contacts close among found may be of TB cases Additional TB. pulmonary smear-negative having as one categorized is some whether decide physician‘s judgement will alone experienced the facilities, of X-ray or, absence the physician in experienced X-ray bypatible an interpreted com a either antibiotics, of trial the after negative again are samples two the if Thus, cases. smear-negative in TB of pulmonary diagnosis to the lead will TB with consistent symptoms X-ray acompatible with together some circumstances, In TB. for tool pulmonary X-ray not is adiagnostic were negative. itself examinations sputum-smear two the if examination sputum further encourage should TB active X-ray with compatible lesions examination. sputum-smear positive by confirmed to be expected are cases TB pulmonary 65%At least of all examination. sputum first the after 2weeks re-examined be should fluoroquinolone).improvement,thepatient’sor any is thereno sputum If but not anti-TB drugs or co-trimoxazole, (e.g. 1week for atbiotics least amoxicillin anti broad-spectrum with infection respiratory for acute treated be should pect sus TB the symptoms, of persistent because suspected still is TB but pulmonary are negative smears sputum two the When on anti-TB treatment. started and registered be then must who patient, TB positive asmear- is smear one positive at least with suspect TB Any method. Neelsen positive is smear sputum one If least at collection. early-morning an from one obtained at least with samples, tum spu two provide should suspect aTB day. the practice, In in later asample than organisms TB to contain more therefore likely is sample sputum morning early an overnight; airways the up in build Secretions for AFB. microscopy binocular light by examined samples (formerly have two should sputum three) suspect TB Each for diagnosis criteria Laboratory * Communicable disease epidemiological profile epidemiological disease Communicable Technical and Advisory Group for Tuberculosis in June 2007. 2007. June in Tuberculosis for Group Advisory and Technical was Strategic andcase WHO theisby recommended endorsed by TB of new definition sputum-smear a This . Smears should be stained using the Ziehl– the using stained be should . Smears . If the initial two smears are negative, negative, are smears two initial the . If -

- - - - - 185

TB in HIV-positive patients HIV-positive patients with TB infection have a much higher risk of developing active TB than HIV-negative patients. Pulmonary TB is still the commonest form of TB in HIV-infected patients. The clinical presentation of TB depends on the degree of immunosuppression. The principles of TB control are the same even when there are many HIV-infected TB patients. It is important to look systemati- cally for symptoms or signs of TB in HIV-positive patients and to start treatment without delay based on bacteriological, radiological and clinical evidence. HIV testing should be promoted among TB patients. HIV-positive TB patients should be provided with co-trimoxazole preventive therapy (CPT). Whenever possible, eli- gible HIV-positive TB patients should be provided with antiretroviral (ARV) therapy.

Diagnostic criteria for classification of TB in adults WHO has recently revised recommendations to diagnose and treat tuberculosis in HIV-prevalent and resource-constrained settings. Pulmonary tuberculosis (pulmonary TB). Pulmonary TB refers to disease involving the lung parenchyma. Tuberculous intrathoracic lymphadenopathy (mediastinal and/or hilar) or tuberculous pleural effusion without lung involvement is a case of extrapulmonary TB. A patient with both pulmonary and extrapulmonary TB TUBERCULOSIS should be classified as a case of pulmonary TB. Smear-positive pulmonary TB. The revised case definition of smear-positive pulmonary tuberculosis is the same for HIV-positive and HIV-negative patients, i.e. I requiring at least one positive smear in settings with a functional system of external quality assurance for smear microscopy. Smear-negative pulmonary TB. The revised case definition of smear-negative pulmonary tuberculosis includes: II

at least two sputum specimens negative for AFB; and radiographical abnormalities consistent with active tuberculosis; and laboratory-confirmation of HIV infection; or III strong clinical evidence of HIV infection; and decision by a clinician to treat with a full course of antituberculosis chemotherapy.

If there is no laboratory-confirmation of HIV infection or if the patient has no IV strong clinical evidence of HIV infection, the following criteria should be used to establish the diagnosis of smear-negative pulmonary TB:

Communicable disease epidemiological profile 186 CENTRAL AFRICAN REPUBLIC AND CHAD dence of HIV infection or not. infection of HIV dence evi clinical strong with presents patient the whether as well oras not, infection HIV of laboratory-confirmation has the patient whether used is definition This for assessment. to ahospital referred be but should suspected be will laryngitis) TB peritonitis, TB of bone or TB joints, meningitis), TB TB, (e.g.forms miliary life-threatening severe as such cases, Other discharge. of caseous production evolution and/or chronic nodes, lymph or axial of cervical swelling with enitis, lymphad peripheral as such to diagnose easy be will chemotherapy. cases Some of antituberculosis course afull with to treat by aclinician decision a medical followed by EPTB, active with consistent evidence clinical or strong histological or specimens, on culture-positive based be should Diagnosis meninges. bones, and joints skin, tract, genitourinary abdomen, nodes, lymph pleura, e.g. lungs, the than other of organs tuberculosis refers to This tuberculosis. Extrapulmonary infection. HIV of evidence clinical strong is there or not whether and firmation con HIV alaboratory is or not there whether case TB pulmonary smear-negative a is positive is result culture sputum subsequent whose and were negative smears sputum initial whose Apatient children. more in but frequent relatively adults in exceptional be should which result, smear without cases includes also group This Communicable disease epidemiological profile epidemiological disease Communicable 50 is relatively occurrence TB of risk The life. throughout may persist latent infections to years; weeks from may take disease TB to active infection TB from Progression Progression to active disease products. or dairy milk of unpasteurized by ingestion usually cattle, to tuberculous exposure from results TB Bovine or sneeze. cough TB geal laryn or pulmonary active with droplet’s The whenpatients are produced nuclei nuclei. droplets’ in included are that bacilli of tubercle transmission Airborne Mode of transmission

2006/tbhiv_recommendations.pdf). (http://www.who.int/entity/tb/publications/ adolescents and adults among tuberculosis extra-pulmonary and pulmonary smear-negative of treatment and diagnosis the Improving see: please settings, prevalent HIV in TB of treatment and diagnosis the on recommendations revised the on information further For decision by a clinician to treat with a full course of antituberculosis chemotherapy. antituberculosis of course full a with treat to clinician a by decision and TB; pulmonary active with consistent abnormalities radiographic and antibiotics; of broad-spectrum to acourse response no clinical and for AFB; negative specimens sputum two at least 50 - - - - 187 high during the first year following TB infection then progressively decreases by half within the following 4–5 years. Only ≤ 10% of infected people with a normal immune system will develop active TB at some point in life.

Communicability period As long as viable tubercle bacilli are being discharged in the sputum. Effective treatment usually eliminates communicability within 8 weeks.

Epidemiology General Various factors present challenges for successful TB control in the subregion. HIV is the most powerful factor known to increase the risk of developing active TB among people infected with tubercle bacilli. Low BCG vaccination coverage among children < 1 year of age and poor nutritional status increase vulnerability to development of active disease.

Geographical distribution

Cases are reported from all subnational levels in the region. TUBERCULOSIS

Seasonality No specific seasonality is reported. I Alert threshold Not applicable. II Risk factors for increased burden Population movement. Population displacement disrupts existing TB control activities. This leads to an increased risk of transmission since TB cases with the III potential to spread the disease will be identified and treated after a long delay or not at all. The proportion of interruptions of TB therapy, TB relapses and treatment failure is also likely to increase. This contributes to the emergence of drug-resistant strains and increasing deaths from TB. IV Overcrowding and poor indoor ventilation are recognized as the important factors leading to increased risk of transmission.

Communicable disease epidemiological profile 188 CENTRAL AFRICAN REPUBLIC AND CHAD active TB. TB. active severe of developing risk at particular to be considered are ages, of all children malnourished especially populations, Malnourished occurrence. of TB risk the increases dysfunction system immune consequent The populations. nourished HIV/AIDS,mal in common is with combination in often TB, shortages. Food (MDR-TB).TB of development of multidrug-resistant causes important ment most one is of the treat of interruption The iterative proper treatment. without high is rate fatality case- The for alonger period. infectious remain treatment and for diagnosis services health access cannot who TB by People affected services. health to access Poor Communicable disease epidemiological profile epidemiological disease Communicable comprises: group patients of This 1month. anti-TB for more received than treatment time at any has who A patient case Previously-treated has: and 4weeks than less for anti-TB drugs for taken or TB who has treatment never had A who patient has New case criteria: the following to according classified be should Patients anti-TB drugs. have taken ever or not they to whether as carefully questioned be should patients all starts, before treatment and of TB, diagnosis the Following Casemanagement Prevention and control measures

teriology (e.g. sputum smear-positive microscopy), following interruption of interruption microscopy), following (e.g. smear-positive sputum teriology bac positive with treatment to who patient returns interruption: after Return TB. extrapulmonary or TB; pulmonary smear-negative sputum or TB; pulmonary smear-positive sputum of anti-TB (new treated). treatment or previously history microscopy); by sputum (assessed status bacteriological of disease; severity site of disease; - - - 189

treatment for 2 months or more. This could be common among recent refugees or internally displaced persons. Failure: a patient who remained, or became again, smear-positive, 5 months or later during treatment; also, a patient who was smear-negative before starting treatment and became smear-positive after the second month of treatment. Therefore, these patients after having failed a previous treatment are started on a re-treatment regimen. Relapse: a patient previously treated for TB who has been declared cured or treatment completed, and is diagnosed with bacteriologically-confirmed (smear or culture-positive) tuberculosis. Chronic: a patient who remained, or became again, smear-positive at the end of a fully supervised, standardized re-treatment regimen.

Good case management includes directly observed therapy during the intensive phase for all new sputum smear-positive cases, the continuation phase of rifampicin- containing regimens and the entire re-treatment regimen. There are three main types of treatment regimens: Category I for new smear- positive pulmonary cases, and severely ill TB patients; Category II for re-treatment cases; and Category III for smear-negative pulmonary or extrapulmonary cases (not severely ill patients) (see Treatment categories below). TUBERCULOSIS The chemotherapeutic regimens are based on standardized combinations of five essential anti-TB drugs: I 1. rifampicin (R) 2. isoniazid (H) 3. pyrazinamide (Z) 4. ethambutol (E) II 5. streptomycin (S).

TB drugs should be given to TB patients in fixed-dose combination forms. Each of the standardized chemotherapeutic regimens consists of two phases: III

1. Initial (intensive) phase 2–3 months, with 3–5 drugs given daily under direct observation, for maximum reduction in the number of TB organisms. IV The number of drugs used relates to the risk of failure of treatment due to possible bacterial resistance.

Communicable disease epidemiological profile 190 CENTRAL AFRICAN REPUBLIC AND CHAD 4. 3. 2. 52 * 2. Communicable disease epidemiological profile epidemiological disease Communicable 51 months: of 6–8 regimens using chemotherapy short-course Standardized Treatment categories 1. HIV-positive patients

grammes should coordinate activities through a TB/HIV coordinating body. coordinating aTB/HIV through activities coordinate should grammes pro HIV the and problemHIV-TB of TB To effectively co-infection, manage patient. the in TB ofexclusion active requires firstly and evaluated, carefully be should IPT use to decision The test). skin (shown tuberculin by apositive infection TB latent with HIV-positive individuals in disease of TB risk the reduces (IPT) preventive treatment isoniazid that have shown studies trial clinical Controlled Continuation phase Continuation containing regimen throughout the 6-month course of the treatment. treatment. of the course 6-month the throughout regimen containing arifampicin- (ii) prescribed be and should tions; HIV-positive patients TB reac skin fatal sometimes and of severe risk increased an is there as patients to HIV-positive TB not administered be should However: (i) thioacetazone for HIV-negative HIV-positive and same patients. the is treatment Anti-TB drug of treatment. 2 weeks first for the ward aseparate in kept be should patients Hospitalized ment supporter. worker byor must be a checked treat of health medication swallowing Actual by staff. given be should regimens of rifampicin-containing doses All form. combination fixed-dose a but in unsupervised, daily for given 6months isoniazid) (ethambutol and of refugees), 2drugs repatriation (e.g. or, during some cases in observation direct under aweek 3times given rifampicin) (including 2–3 drugs with months, 4–6 Additionally, please see NTCP guidelines. NTCP see please Additionally, control tuberculosis effective for work frame DOTS expanded An revision); under (WHO/TB/97.221, 1997 Organization, World Health Geneva, manual field inter-agency an situations: refugee in control Tuberculosis (WHO/TB/2003.313); 2003 tion, programmes national for guidelines tuberculosis: of Treatment See: guidelines. NTCP consult please Additionally, HTM_TB_2004.330.pdf). http://whqlibdoc.who.int/hq/2004/WHO_ WHO/HTM/HIV/2004.1; (WHO/HTM/TB/2004.330, 2004 activities TB/HIV collaborative on policy interim WHO/TB-HIV See: week. per 3times only given each but regularly given isoniazid and rifampicin of This 4months by daily. followed is given are ethambutol and pyrazinamide isoniazid, rifampicin, treatment, of months 2 first the for that means RHZE/4H3R3 2 e.g. therapy, the of phases different the separates “/“ symbol The given. is age dos daily a letter, the after no number is there If letter. the after written week per doses the and letter the of front in given be to is medication the months of number the with form short in written are Regimens 52 51 . Geneva, World Health Organization, 2002 (WHO/CDS/TB/2002.297). (WHO/CDS/TB/2002.297). 2002 Organization, World Health . Geneva, * , 3rd ed. Geneva, World Health Organiza World Health Geneva, ed. , 3rd . Geneva, World Health Organization, Organization, World Health . Geneva, . ------191

Category I (EHRZ/RH) These patients are: new smear-positive TB cases; and severely ill patients with other forms of TB (new smear-negative pulmonary TB with extensive parenchymal involvement, and new cases of severe forms of extrapulmonary TB). The recommended regimen is for 6 months. The initial (or intensive) phase of treatment lasts for 2 months, with rifampicin, isoniazid, pyrazinamide and ethambutol given daily or 3 times a week, under direct supervision. At the end of the second month, most patients will have a negative result on sputum microscopy; they may then progress to the second stage of treatment – the continuation phase. This phase lasts for 4 months, with rifampicin and isoniazid given 3 times per week, under direct supervision. If the sputum-smear examination is positive at the end of the second month, the initial phase is prolonged for a third month. The patient then starts the continuation phase irrespective of the results of the sputum examination at the end of the third month. In the continuation of the treatment, if the smears are still positive at the end TUBERCULOSIS of the fifth month or at the end of the treatment regimen, the patient is classified a treatment failure case. The patient is re-registered, and commences a full course of the re-treatment regimen as a Category II patient. I The drug dose is adjusted for weight gain at the end of the initial phase (second or third month). This category includes patients with TB meningitis, disseminated TB, peri- carditis, peritonitis, bilateral or extensive pleurisy, vertebral disease with II neurological complications, and intestinal and genitourinary disease. Daily self-administered ethambutol and isoniazid may be used in the continuation phase for 6 months, so this treatment regimen takes a total of 8 months. However, note that there is a higher rate of treatment failure and relapse III associated with this regimen using ethambutol and isoniazid in the continuation phase.

Category II (2SHRZE/1HRZE/5HRE) IV This category should be used for patients who were previously treated and are now sputum smear-positive. This includes:

Communicable disease epidemiological profile 192 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable in: indicated is regimen III Category The III Category

should be checked. be should of medication swallowing supporter. treatment Actual or a by staff observed directly be should regimens of rifampicin-containing doses All 6 months. for phase continuation the in used be should isoniazid and ethambutol daily observation, direct out under carried be cannot phase continuation the When children). in observed usually TB primary matic sympto (including TB extrapulmonary non-serious with children and adults examination. sputum of the results of the regardless phase, continuation to the progress month fourth end of the at the positive still are who for 1more Patients month. ethambutol and pyrazinamide rifampicin, isoniazid, with extended is of treatment phase initial the month, third of the end at the smear-positive sputum month). is patient the eighth If end of the treatment the endthe of andmonth) at (at (at fifth endtreatment of the the of phase continuation the month), during (at third endtreatment of the the of phase initial end of the at the performed is examination Sputum-smear week. per 3times given ethambutol and rifampicin isoniazid, with treatment of 5 months phase is continuation followed by a regimen this of phase initial The 2 months. first for the daily by streptomycin supplementedis regimen This daily. given are ethambutol and pyrazinamide rifampicin, isoniazid, where for 3 months, lasts treatment of phase initial The of treatment. phases both throughout vised These patients should receive a standardized re-treatment regimen,fully super mary TB. TB. mary pri with children HIV-negative to be in and known are who TB pulmonary smear-negative involvement, non cavitary parenchymal limited with patients in of treatment phase initial the in However, omitted may be ethambutol patients. I Category as regimen treatment same the receive patients These involvement); parenchymal limited (with TB pulmonary smear-negative with patients

relapse after treatment. after relapse treatment failure; and failure; treatment interruption; after treatment

- - - 193

Health education Key elements of community education emphasize:

destigmatization of TB patients; curability of TB disease; early (self) referral of TB suspects; the importance of adherence to treatment; contact-tracing and investigation.

The most important messages to teach are:

TB in adults should be suspected when the person has a productive cough of long duration (> 2weeks) or in accordance with the directives of the NTCP, and/or blood in sputum, with significant weight loss. Cover the mouth whenever coughing or sneezing to prevent the spread of microorganisms. Anyone may contract TB.

TB is curable. TUBERCULOSIS Early treatment is important for best results and to prevent spread, especially to family members. Children are especially at risk if not treated and may develop severe, even fatal I forms of TB. Identification of TB and appropriate treatment constitute the best prevention. All TB patients must take the full course of treatment prescribed. II Treatment makes patients non-infectious in 8 weeks, but cure takes 6–8 months. Treatment must be completed even though the patient may feel better sooner. Interruption of treatment may result in a recurrence of TB, which may be diffi III cult or impossible to treat and spread TB bacilli to others, especially to children. All patients should be treated sympathetically and with respect. Controlling TB is a community responsibility. IV Note. Diagrams should be used as much as possible: a high literacy should not be assumed. Cured patients are often helpful teachers and supporters of new patients.

Communicable disease epidemiological profile 194 CENTRAL AFRICAN REPUBLIC AND CHAD interventions to prevent the transmission of TB. Complementary control strategies: control Complementary of TB. transmission to prevent the interventions effective most the are cases TB (infectious) of smear-positive treatment and Detection Prevention Communicable disease epidemiological profile epidemiological disease Communicable forms extrapulmonary of children, number alarge with situations plex emergency com In infectious. rarely are they so TB, pulmonary have smear-positive rarely body.the Children of anypart may affect which disease, ageneral is children in TB children in of TB Diagnosis Management of TB in displaced populations not is recommended. BCG with Revaccination children. for all programmes tion immuniza into routine incorporated be should of newborns vaccination The it. received have who not already of 5years age up to the children any and children newborn for all recommended strongly is BCG increased. is to children mission trans of TB risk the populations, displaced and refugee many in common are malnutrition and overcrowding As children. in TB miliary and meningitis TB as such disease of severe forms in preventing effective to be shown been has BCG Immunization

require prophylaxis, but only clinical follow-up. clinical but only prophylaxis, require do not areand well whoover 5 aged years aChildren after 1-weekinterval). (preferably programme the leaves child before the given be should BCG and stopped, may be isoniazid programme, the in event of disruption asudden the in course; prophylaxis isoniazid the out after carried may be vaccination BCG well, is child the If prophylaxis. for group isoniazid important most the are mothers smear-positive of sputum children Breastfeeding occurrence. disease TB of likelihood the reduce significantly will 2months).up (e.g. every This follow- a steady for with 6 months 5mg/kg/day follows: as prophylaxis isoniazid receive should TB, have active no investigation, who, after and patients TB pulmonary of smear-positive contacts close are who of age <5years Children individuals. HIV-positive from patients below). TB (see Immunization children in of to prevent TB BCG forms severe infectious separate to care Particular of treatment. 2 weeks first the for at least ward adedicated in patients of hospitalized ration sepa and clinics, health of in overcrowding reduction and ventilation Good to treatment. adherence strengthen to improve and education Health - - - -

195 of TB should be suspected, diagnosed and treated appropriately. Often, this requires referral to a hospital for X-ray and special examinations (e.g. lumbar puncture in case of meningitis TB suspicion). Children with headache, change of temperament, recent squint or ocular muscle paralysis should be suspected of meningitis. TB is one, albeit rare, cause of meningitis (meningococcal meningitis is a more common cause in complex emergency settings). Definitive diagnosis requires hospital referral. Children with high fever, dyspnoea, gastrointestinal symptoms, confusion (i.e. those in whom acute miliary TB is suspected) must also be referred to hospital for assessment and diagnosis. Suspected TB of the bone, tuberculous arthritis or pleural effusions also require referral. Commoner forms of extrapulmonary disease (e.g. cervical or axillary lymphad- enitis, peritonitis with ascites) can be diagnosed and treated in a camp situation. The diagnosis of TB in children should be considered in a child if there is:

an illness lasting for more than 10 days;

a history of close contact with a TB patient; TUBERCULOSIS a poor response to antibiotic therapy; a poor response to one month of nutritional rehabilitation; weight loss or abnormally slow growth; I loss of energy; or increasing irritability and drowsiness.

Note. The same considerations explained above for adults apply to children for II the diagnosis of TB in HIV-positive patients.

III

Communicable disease epidemiological profile 196 CENTRAL AFRICAN REPUBLIC AND CHAD a blood specimen. a blood with case at 1suspected investigating districts ≥80% and population 100per 000 ≥2.0 rate (investigation objectives performance surveillance attained also has and mid-2006 since operational been has fever surveillance yellow Case-based Outbreaks: Central African Republic Country-specific disease burden YELLOWFEVER Communicable disease epidemiological profile epidemiological disease Communicable 54 53 Flavivirus to the belonging Yellow fever virus, Infectious agent Description 2006. since reported have been No cases Chad

monitoring/en/globalsummary/timeseries/tsincidencemea.htm. http://whqlibdoc.who.int/hq/2007/WHO_IVB_2007_eng.pdf; http://www.who.int/immunization_ erage of 105% in the target population of 10 000 inhabitants. of 10 population 000 of 105% target erage the in cov administrative areported with were people vaccinated, 6000 completed. was campaign vaccination Amass investigation. by entomological detected Aedes were on found investigation. cases No additional locality. II Boyali the in avillage in prefecture, Bossembele the from ported re was and jaundice of fever case alaboratory-confirmed November 2006: of%. 98.7 coverage administrative areported Kouazo); with 519 and 56 Gbabiri were people vaccinated, Dan Danayénin, Bozoum, Bolé, (Birvan communes five in June 2008 in organized was campaign vaccination mass A reactive 50%. CFR death; 1 confirmed); (one laboratory- cases was 2suspected prefecture; Ouham-Pendè 2008: April http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencemea.htm. 53

54 group. mosquitoes were not mosquitoes -

- 197

Case definition Clinical description Characterized by acute onset of fever followed by jaundice within 2 weeks of onset of first symptoms. Haemorrhagic manifestations and signs of renal failure may occur. There are two disease phases of yellow fever:

Acute phase. While some infected people have no symptoms at all, this first phase is normally characterized by fever, muscle pain (with prominent back- ache), headache, shivers, loss of appetite, nausea and/or vomiting. Often, the high fever is paradoxically associated with a slow pulse (Faget’s sign). Most patients improve after 3–4 days and their symptoms disappear, but 15% enter the toxic phase. Toxic phase. Fever reappears, the patient rapidly develops jaundice and com- plains of abdominal pain with vomiting. Bleeding may occur from the mouth, nose, eyes and/or stomach. Once this happens, blood appears in the vomit and faeces. Kidney function deteriorates; this may range from abnormal protein levels in the urine (albuminuria) to complete renal failure with no urine

production (anuria). Half the patients in the toxic phase die within 7–10 days YELLOWFEVER after onset. The remainder recover without significant organ damage.

Laboratory criteria I Isolation of yellow fever virus; or presence of yellow fever-specific IgM or a fourfold or greater rise in serum IgG levels in paired sera (acute and convalescent); or positive postmortem liver histopathology; or II detection of yellow fever antigen in tissues by immunohistochemistry; or detection of yellow fever virus genomic sequences in blood or organs by polymerase chain reaction (PCR). III Case classification Suspected: a case that is compatible with the clinical description. Probable: not applicable. IV Confirmed: a suspected case that is laboratory-confirmed (national reference laboratory) or epidemiologically-linked to a confirmed case or outbreak.

Communicable disease epidemiological profile 198 CENTRAL AFRICAN REPUBLIC AND CHAD (all-day biting species). biting (all-day aegypti A. is vector the areas, urban quitoes remain so for life. for so life. remain quitoes mos infected, Once coexist. mosquitoes vector abundant and people susceptible many where communicable highly is disease The illness. days of 3–5 first for the and beforeof fever onset shortly for mosquitoes infective is patients of The blood period Communicability From 3to 6days. Incubation period Aedes the from mosquitoes are Africa in areas in fever forest ofyellow vectors The mosquitoes. infective The bite of Mode of transmission Communicable disease epidemiological profile epidemiological disease Communicable urban: and intermediate Sylvatic, Africa. in for fever occur yellow cycle of transmission types three All poisoning). dengue, typhoid, (e.g. malaria, more diseases common other with confused easily and stages early the during recognize to difficult is disease the and suboptimal, is surveillance as especially epidemics into regular amplify may presence viral The endemic). (i.e. infection lowof levels with present constantly is virus The 15 to 10 from °N aband °S. within lie Chad, southern and CAR include which from fever.yellow countries, These risk are at Africa in countries Thirty-three distribution Geographical facility. ahealth in care not seek at does home and treated to be likely is patient the because may go undetected cases Mild alone. symptoms and signs on the based diagnosis definitive a make to workers health for difficult therefore it is diseases; other of many those overlap with and spectrum have awide symptoms and signs the because Moreover, fever of may yellow go undetected outbreak remote areas. an surveillance is not adequate to detect cases of sylvatic yellow fever that may occur in Disease not fever by is known. yellow caused death and of illness extent precise The increasing. are populations susceptible and habitats mosquito Mosquitoes, years. 20 past over the rise on the have been fever epidemics yellow Globally, General Epidemiology A. africanus A. species: A. simpsoni , A. A. furcifer , A. . In . In - 199

Sylvatic yellow fever generally results in sporadic cases most commonly among young men working in the forest. Intermediate yellow fever results in small-scale epidemics and occurs in humid or semi-humid savannah. Separate villages in an area suffer simultaneous cases. Urban yellow fever results in large epidemics that tend to spread outwards from one source to cover a wide area.

Seasonality In forested areas where the yellow fever virus circulates between mosquitoes and monkeys, the disease is continuously present throughout the year. In field or savannah areas outside the forest areas, transovarian transmission may contribute to maintenance of the virus even during the dry season.

Alert threshold One confirmed case should be considered as an epidemic and lead to the rapid implementation of control measures. Yellow fever is a significant public health problem in the subregion, where cases have been periodically reported for several decades. The risk of resurgence of major epidemics of yellow fever, particularly in heavily populated urban settings, is increasing for many reasons, including low immunization coverage, the invasion of urban settings by A. aegypti and the change YELLOWFEVER in the demographic balance in most countries, shifting populations from being mostly rural to mostly urban. I Risk factors for increased burden Population movement. Unvaccinated people moving to areas of endemicity are at risk. Changes in land use constitute a risk factor. The movement of people from rural to urban areas during emergencies may result in large numbers of people II living in conditions of poverty, crowded housing and poor sanitation, all of which are conditions that amplify the risk of transmission. Overcrowding. As a result of increased population density and increased exposure to mosquito bites in temporary shelters. III Poor access to health services

Collapse of vaccination programmes. Increased death rates due to lack of appropriate case management. IV Weak mosquito control programmes and persistent low vaccination coverage rates for yellow fever exacerbate the risk.

Communicable disease epidemiological profile 200 CENTRAL AFRICAN REPUBLIC AND CHAD Under epidemic conditions, the following must be implemented: be must following the Under conditions, epidemic cities. into and to village village from spreads epidemic the mosquitoes, infected or humans of infected patterns travel on the Depending place. in are epidemic an for conditions the established, is transmission human-to-human indirect When humans. it fever when bites non-infected yellow spreads mosquito infected An Epidemiccontrol Casemanagement Prevention and control measures Communicable disease epidemiological profile epidemiological disease Communicable 1. control for fever programmes: yellow are recommended strategies The following women. for pregnant notit is recommended reasons, for theoretical individuals; immunosuppressed or other persons infected HIV- for Yellow symptomatic not is recommended fever vaccine campaigns. tive preven mass and programmes immunization child routine in fever vaccine yellow of incorporation the through routinely given be must vaccination areas, endemic fever. yellow for preventing In measure important most single Vaccination the is Prevention

Emergency mosquito-control measures: mosquito-control Emergency fever vaccine. yellow with vaccination Mass available. outcome may improve but rarely the is care supportive Intensive salts. rehydration oral with fevercorrected may be and Dehydration is for treatment available. fever yellow No specific introduced yellow fever vaccine in routine immunization. routine in fever vaccine yellow introduced 1989, In CAR at-risk areas. in on Immunization Programme Expanded of the activities routine in integrated be should fever vaccination yellow population; of the 50% at 14 least to reach and 9months years between aged children cinate to vac be would alower-cost intervention limited, are funds if 80%; than less is wherecoverage districts over in 9months aged population the Vaccinating

use of insecticide-treated bednets for hospitalized cases. for hospitalized bednets of insecticide-treated use spraying to kill adult mosquitoes (less important because of small impact); of small because important (less adult mosquitoes to kill spraying for fever control); yellow measure control quito mos (the sites important most breeding mosquito potential eliminating - - - 201

2. Where necessary, mass vaccination campaigns to prevent epidemics. 3. Improved disease surveillance to enable early outbreak detection and rapid response. 4. Implementation of effective vector control measures for A. aegypti in urban centres.

Yellow fever surveillance is critical for monitoring the incidence of the disease and allowing the prediction and early detection of outbreaks and the monitoring of control measures. Case-reporting of yellow fever is universally required by the International Health Regulations (IHR).

YELLOWFEVER

III

Communicable disease epidemiological profile 202 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable PART IV

Annexes

1. Main indicators, Central African Republic African Central indicators, 1. Main CentralA. African Republic Key national indicators and general information ANNEX 1 Indicator Most recent population census population recent Most Estimated population Estimated Life expectancy at birth at expectancy Life Neonatal mortality rate per 1000 live births live 1000 per rate mortality Neonatal Infant mortality rate (< 1 year) per 1000 live births live (< 1000 per rate 1year) mortality Infant < 5 mortality rate per 1000 live births live 1000 per rate < 5mortality < 5 mortality ranking < 5mortality Low-birth-weight infants Low-birth-weight < 5wasting < 5 underweight, moderate and severe and moderate < 5underweight, < 5 severely underweight < 5severely < 5 with stunting, moderate and severe and moderate stunting, < 5with Births attended by skilled personnel skilled by attended Births Maternal mortality ratio (adjusted) per 100 000 100 per (adjusted) ratio mortality Maternal Nurses/midwives per 10 000 per Nurses/midwives Physicians per 10 000 per Physicians Population using improved drinking-water sources drinking-water improved using Population Population living on < 1 US$ per day <1US$ per on living Population Adult literacy Adult Human development ranking development Human Human Poverty Index Poverty Human Communicable disease epidemiological profile epidemiological disease Communicable Value December 2003 December 3 151 rural 62% 072, 44 48 115 175 15/189 13% including 4.7%severe cases 10.5% 29% 8% 38% 53% 980 1.4 0.4 75% 66% 48.6% 171/177 98/108 Source UN statistics, August 2008 2008 August statistics, UN UN statistics, August 2008 2008 August statistics, UN UN Population Division, 2006 UNICEF, 2000 UNICEF, 2006 UNICEF, 2006 UNICEF, 2006 UNICEF, 1999–2006 survey, 2000 survey, cluster indicator Multiple UNICEF, 1996–2006 UNICEF, 2000–2006 UNICEF, 2000–2006 UNICEF, 2000–2006 UNICEF, 2005 WHO, 1995 WHO, WHO, 1995 WHO, UNICEF, 2004 UNDP, 2006 WHO, 2004 WHO, UNDP, 2005 UNDP, 2005 205 IV III II I ANNEXES 206 CENTRAL AFRICAN REPUBLIC AND CHAD http://hdr.undp.org/en/statistics/ http://www.unicef.org/infobycountry/car_statistics.html http://www.unicef.org/infobycountry/index.html http://www.who.int/hac/crises/caf/sitreps/car_jan2007.pdf http://www.who.int/hac/crises/en/ http://unstats.un.org/unsd/demographic/products/vitstats/serATab2.pdf Communicable disease epidemiological profile epidemiological disease Communicable 2. Administrative information, Central African Republic

Prefectures: 14, including 2 economic prefectures Sub-prefectures: 71

Prefectures, Central African Republic Communicable disease epidemiological profile epidemiological disease Communicable 207 IV III II I ANNEXES 208 CENTRAL AFRICAN REPUBLIC AND CHAD 3. History of natural disasters, Central African Republic African Central disasters, of natural 3. History Communicable disease epidemiological profile epidemiological disease Communicable 1996 (October) 2000 (January) 2004 (November) 2005 (August) 2007 (September) Year Floods Floods Floods Floods Floods Type ofdisaster 2008 2007 2006 2005 2003 2002 2001 1999 1997 1996 1993 1981 1979 1965 1960 1958 Republic African Central emergencies, of humanitarian Chronology 4. http://www.reliefweb.int/rw/RWB.NSF/db900SID/LSGZ-7AWJYR?OpenDocument http://news.bbc.co.uk/2/hi/africa/country_profiles/1067615.stm Civil servants strike; prime minister and cabinet resign cabinet and minister prime strike; servants Civil border crossing Darfur from civilians to protect force authorized peacekeeping UN Bozize with accord People's Frontpeace Rebel signs Democratic control helps regain support French air north-east; in town seize Rebels Chad region for north-western lawless flee Thousands Bangui of capital Flooding Patasse deposes successfully Bozize Patasse to overthrow Bozize by General attempt help a further subdue forces again Libyan-backed Bozize General of staff chief forces of army with clash troops Government coup Kolingba suppresses troops, Congolese and Chadian by Libyan, assisted Patasse, re-elected Patasse French troops replace peacekeepers African mutiny Soldiers rule military of 12 years ending elections, in Dacko and Kolingba beats Patasse by Kolingba deposed Dacko coup by Dacko in ousted Bokassa Bokassa) Jean-Bedel coup (army commander Military independent becomes Republic African Central Africa French Equatorial within Self-government Communicable disease epidemiological profile epidemiological disease Communicable 209 IV III II I ANNEXES 210 CENTRAL AFRICAN REPUBLIC AND CHAD zens residing in Cameroon, Chad and Sudan. and Chad Cameroon, in residing zens citi CAR 000 98 2008: March of 28 web site as OCHA/Relief to the According Republic African Central from Refugees 6. http://www.wfp.org/operations/current_operations/project_docs/101892.pdf Humanitarian%20Action%20Update%20Central%20African%20Republic http://www.reliefweb.int/rw/rwb.nsf/db900sid/EGUA-7DBL2F?OpenDocument&query=UNICEF%20 000. 197 2008: March 28 as of siteweb (OCHA)/Relief Affairs Humanitarian of Coordination the for Office United Nations to the According Republic African Central persons, displaced 5. Internally Communicable disease epidemiological profile epidemiological disease Communicable http://www.wfp.org/operations/current_operations/project_docs/101892.pdf http://www.reliefweb.int/rw/RWB.NSF/db900SID/LSGZ-7AWJYR?OpenDocument

- 7. National immunization schedule, Central African Republic African Central schedule, 7. immunization National http://whqlibdoc.who.int/hq/2007/WHO_IVB_2007_eng.pdf http://www.unicef.org/publications/files/Immunization_Summary_2007.pdf 2007. WHO-IVB/UNICEF, Source: Republic African Central coverage, Immunization 8. http://www.who.int/immunization_monitoring/routine/en/ http://www.who.int/immunization_monitoring/en/globalsummary/ScheduleResult.cfm http://whqlibdoc.who.int/hq/2007/WHO_IVB_2007_eng.pdf http://www.unicef.org/publications/files/Immunization_Summary_2007.pdf 2008. WHO-IVB/UNICEF, Source: TT2 +PABTT2 Polio 3 Measles DPT 3 BCG Antigen BCG Vaccine DTwP Measles OPV TT YF Bacille Calmette–Guérin vaccine Calmette–Guérin Bacille whole cell pertussis whole cell pertussis Diphtheria andtetanus toxoid with Measles vaccine Oral poliovaccine Tetanus toxoid Yellow fever Communicable disease epidemiological profile epidemiological disease Communicable 56 36 35 40 70 Coverage (%)for 2006 Schedule Birth 6, 10,14weeks 9 months Birth; 6,10,14weeks Birth; + 1year and+1year + 1month, +6months; Pregnant women 9 months 211 IV III II I ANNEXES 212 CENTRAL AFRICAN REPUBLIC AND CHAD 1. Main indicators, Chad indicators, 1. Main ChadB. Communicable disease epidemiological profile epidemiological disease Communicable http://hdr.undp.org/en/statistics/ http://www.unicef.org/infobycountry/chad_statistics.html http://www.unicef.org/infobycountry/index.html http://www.who.int/hac/crises/en/ http://www.who.int/hac/crises/tcd/sitreps/chad_jan2007.pdf http://unstats.un.org/unsd/demographic/products/vitstats/serATab2.pdf Indicator Most recent population census population recent Most Estimated population Estimated Life expectancy at birth (M/F) birth at expectancy Life Neonatal mortality rate per 1000 live births live 1000 per rate mortality Neonatal Infant mortality rate (< 1 year) per 1000 live births live (< 1000 per rate 1year) mortality Infant < 5 mortality rate per 1000 live births live 1000 per rate < 5mortality < 5 mortality ranking < 5mortality Low-birth-weight infants Low-birth-weight < 5 underweight, moderate and severe and moderate < 5underweight, < 5 suffering from wasting, moderate and severe and moderate wasting, from < 5suffering < 5 severely underweight < 5severely < 5 with stunting, moderate and severe and moderate stunting, < 5with Births attended by skilled personnel skilled by attended Births Maternal mortality ratio (adjusted) per 100 000 100 per (adjusted) ratio mortality Maternal Nurses/midwives per 10 000 per Nurses/midwives Physicians per 10 000 per Physicians Population using improved drinking-water sources drinking-water improved using Population Population living below national poverty line poverty national below living Population Adult literacy Adult Human development ranking development Human Human Poverty Index Poverty Human Value April 1993 April 6 279 931, 75% rural 44/47 45 124 209 7/189 22% 37% 14% 14% 41% 16% 1500 1.7 0.3 42% 64% 48.6% 170/177 108/108 Source UN statistics, April 2008 2008 April statistics, UN UN statistics, August 2008 2008 August statistics, UN WHO, 2003 WHO, UNICEF UNDP, 2004 UNICEF, 2006 UNICEF, 2006 UNICEF, 1999–2006 UNICEF, 1996–2006 UNICEF, 2000–2006 UNICEF, 2000–2006 UNICEF, 1996–2006 WHO, 2000 WHO, UNICEF, 2000–2006 WHO, 2001 WHO, WHO, 2001 WHO, UNICEF, 2004 UNDP, 2006 WHO, 2004 WHO, UNDP, 2007–2008 UNDP, 2004 Administrative divisions, Chad http://www.theglobalfund.org/search/docs/7TCDM_1488_0_full.pdf 54 Departments: 18 Regions/provinces: Chad information, Administrative 2. Communicable disease epidemiological profile epidemiological disease Communicable 213 IV III II I ANNEXES 214 CENTRAL AFRICAN REPUBLIC AND CHAD 3. History of natural disasters, Chad disasters, of natural 3. History Communicable disease epidemiological profile epidemiological disease Communicable 1981 (November) 1984 (November) 1985 (July) 1988 (September) 1999 (August) 2001 (September) 2004 (August) 2007 (August) Year Drought Drought Floods Floods Floods Floods Locusts Floods Type ofdisaster 2008 2007 2006 2004 2003 1998 1990 1987 1977 1975 1963 1960 1913 Chad emergencies, of humanitarian Chronology 4. http://news.bbc.co.uk/2/hi/africa/1068745.stm and Sudanese militia violence; Sudan breaks off diplomatic relations off breaks Sudan violence; militia Sudanese and May, in Chadian Sudan; and Chad between Senegal in March in signed accord peace Chad; in violence from refugees force Darfur to protect EU approvespeacekeeping N'Djamena; capital offensive reaches Rebel force peacekeeping UN/European authorizes Council Security UN Sudan bordering areas eastern in declared of emergency State over border to Chad spills fighting Darfur; to escape refugees of Sudanese arrival impact; Darfur to Cameroon) (pipeline exporter oil an becomes Chad rebellion armed begins (MDJT) Chad in Justice and Movement for Democracy Deby president, Idriss current and ally, presidential by led aformer Sudan in based rebels President toppled by Libyan-backed north the from force Libya US Frenchassistance and governmentwith Chadian north assists Libya acoup in killed and President deposed war aguerrilla into escalates that parties of political by banning north Muslim in Violence triggered south animist and Christian predominantly and north Arab-Muslim mainly the tension between interethnic from stemming largely violence and by instability marked is history post-independence Chad's Independence: completeFrench of Chad conquest Communicable disease epidemiological profile epidemiological disease Communicable

215 IV III II I ANNEXES 216 CENTRAL AFRICAN REPUBLIC AND CHAD http://www.wfp.org/country_brief/indexcountry.asp?country=148 action%20in%20Chad:%20Facts%20and%20figures%20snapshot%20report http://www.reliefweb.int/rw/rwb.nsf/db900sid/EDIS-7FFRGV?OpenDocument&query=Humanitarian%20 57 000. Republic, African Central from 000; 250 Sudan, from of 9June 2008: web site as OCHA/Relief to the According Chad in Refugees 6. http://www.wfp.org/country_brief/indexcountry.asp?country=148 http://www.reliefweb.int/rw/RWB.NSF/db900SID/EGUA-7AWQRT?OpenDocument 000. 180 2008: as of siteweb (OCHA)/Relief 16 January Affairs Humanitarian of Coordination the for Office United Nations to the According Chad persons, displaced 5. Internally Communicable disease epidemiological profile epidemiological disease Communicable 7. National immunization schedule, Chad schedule, 7. immunization National http://whqlibdoc.who.int/hq/2007/WHO_IVB_2007_eng.pdf http://www.unicef.org/publications/files/Immunization_Summary_2007.pdf 2007. WHO-IVB/UNICEF, Source: Chad coverage, Immunization 8. http://www.who.int/immunization_monitoring/en/globalsummary/ScheduleResult.cfm http://whqlibdoc.who.int/hq/2007/WHO_IVB_2007_eng.pdf http://www.unicef.org/publications/files/Immunization_Summary_2007.pdf 2007. WHO-IVB/UNICEF, Source: TT2 +PABTT2 Polio 3 Measles DPT 3 BCG Vaccine BCG Vaccine DTwP Measles OPV TT Y F Bacille Calmette-Guérin vaccine Calmette-Guérin Bacille acellular pertussis vaccine pertussis acellular with toxoid tetanus and Diphtheria Measles vaccine Measles Oral polio vaccine polio Oral Tetanus toxoid Tetanus Yellow fever Yellow Communicable disease epidemiological profile epidemiological disease Communicable 39 36 23 20 40 Coverage (%)for 2006 Time of administration of Time Birth 6, 10, 14 weeks 10,6, 14 weeks 9 months Birth; 6, 10, 14 weeks 10, 6, 14 weeks Birth; + 1 year and + 1 year +1year and + 1year +1, +26months; pregnancy; contact 1st 9 months 217 IV III II I ANNEXES 218 CENTRAL AFRICAN REPUBLIC AND CHAD http://www.reliefweb.int/rw/rwb.nsf/db900SID/LPAA-7FNM54?OpenDocument&rc=1&emid=SKAR-6JKEX4 2008) Mayof (as IDP figures Chad: Eastern unhcr_RFG_tcd080328-d.pdf?OpenElement http://www.reliefweb.int/rw/fullMaps_Af.nsf/luFullMap/1D54E6D8C36FCB798525741A005BC96A/$File/ 2008) (as of 29 February breakdown sex and age populations: camp refugee Registered resources Map ANNEX 2 Communicable disease epidemiological profile epidemiological disease Communicable http://www.reliefweb.int/rw/rwb.nsf/db900sid/PANA-79NHB7?OpenDocument&rc=1&cc=caf http://www.usaid.gov/locations/sub-saharan_africa/countries/sudan/ http://www.usaid.gov/locations/sub-saharan_africa/sudan/images/satellite/index.html http://ochaonline.un.org/chad/MapCentre/tabid/3640/Default.aspx http://www.reliefweb.int/rw/RWB.nsf/doc404?OpenForm&cc=caf&rc=1 https://www.cia.gov/library/publications/the-world-factbook/geos/cd.html http://www.reliefweb.int/rw/rwb.nsf/db900sid/LRAY-7BRKFM?OpenDocument&rc=1&cc=caf (as 2007) Republic of December African Central the IDPs in http://www.reliefweb.int/rw/rwb.nsf/db900sid/LPAA-7HNQZ3?OpenDocument&rc=1&cc=caf IDP movements and (as of 2008) refugee Republic: African Central Global Alert and Response (GAR) Response and Alert Global Headquarters http://afro.who.int/ddc/index.html (DDC) Control Prevention and Disease of Communicable Division Africa for Office Regional World Organization Health WHO information sources ANNEX 3 http://www.who.int/entity/child_adolescent_health/documents/9241593180/en/ http://www.who.int/entity/child_adolescent_health/documents/9241593180/en/ workers (2005) health senior and other for physicians manual a diarrhoea; of treatment The http://www.who.int/fch/depts/cah/resp_infections/en/ children in infections tract respiratory Acute http://www.who.int/child_adolescent_health/documents/9241546700/en/index.html for children care of hospital book Pocket http://www.who.int/child_adolescent_health/documents/emergencies/en/index.html documents Emergencies emergencies in health Child http://www.who.int/trypanosomiasis_african/en/ (sleeping sickness) trypanosomiasis African Human trypanosomiasis African http://www.who.int/fch/depts/cah/resp_infections/en/ children in infections tract Acute respiratory infections Acute lower tract respiratory http://www.who.int/hac/en/ (HAC) Crises in Action Health http://www.who.int/diseasecontrol_emergencies/en/[email protected] (DCE) Emergencies Humanitarian in Control Disease http://www.who.int/csr/en/ Communicable disease epidemiological profile epidemiological disease Communicable 219 IV III II I ANNEXES 220 CENTRAL AFRICAN REPUBLIC AND CHAD http://www.who.int/child_adolescent_health/news/2008/09_01/en/index.html as hospital effective as just pneumonia severe with forHome children treatment http://whqlibdoc.who.int/publications/2006/9789241594370.cb_eng.pdf settings HIV forIMCI high http://www.who.int/child_adolescent_health/documents/IMCI_chartbooklet/en/index.html 2006) (WHO/UNICEF, booklet chart IMCI http://www.emro.who.int/cah/pdf/imci_technical_updates.pdf (2005) illness of childhood management integrated on the guidelines of the updates Technical Communicable disease epidemiological profile epidemiological disease Communicable http://whqlibdoc.who.int/publications/2005/9241546166_eng.pdf (2005) manual afield emergencies: in control disease Communicable emergencies control in disease Communicable http://www.who.int/cholera/technical/DiarrhoealDiseaseKits/en/index.html note (2006) information kits: disease diarrhoeal Interagency http://www.who.int/topics/cholera/control/en/index.html control prevention and Cholera: http://www.cdc.gov/ncidod/dbmd/diseaseinfo/cholera/top.pdf (1999) cholera and dysentery of epidemic diagnosis for the methods Laboratory http://www.who.int/cholera/tsunami_choleravaccine/en/index.html areas tsunami-affected in use for statement vaccine cholera Joint WHO/UNICEF http://www.who.int/csr/resources/publications/cholera/WHO_EMC_DIS_97_6/en/ environ on cards technical control: (1997) diseases sanitation mental diarrhoeal epidemic other and Cholera diseases) diarrhoeal (seeCholera also http://www.ennonline.net/ife/view.aspx?resid=6 emergencies in feeding on infant guidance Operational http://www.who.int/hiv/topics/paediatric/en/index.html HIV with living of children treatment and HIV Paediatric health/New_Publications/CHILD_HEALTH/PB/00.PB_full_low.pdf http://www.who.int/child-adolescent- (2005) resources limited with illnesses common of management for the guidelines for children: care of hospital book Pocket - dysenteriae due to Shigella epidemics including of control shigellosis, for the Guidelines http://www.who.int/cholera/publications/first_steps/ diarrhoea of acute outbreak an for managing steps First http://www.who.int/cholera/publications/cholera_outbreak/ preparedness improving and response outbreak the assessing outbreak: Cholera http://www.who.int/cholera/publications/critical_steps/ steps complex critical emergencies: in diseases diarrhoeal Acute cholera) (see also diseases Diarrhoeal http://www.who.int/water_sanitation_health/emergencies/qa/en/index.html of emergencies case in questions asked Frequently http://www.who.int/water_sanitation_health/hygiene/envsan/technotes/en/index.html for notes emergencies technical WHO http://www.who.int/water_sanitation_health/emergencies/emergencies2002/en/index.html guide apractical disasters: and emergencies in health Environmental http://www.who.int/water_sanitation_health/dwq/gdwq3rev/en/index.html (3 quality for drinking-water Guidelines emergencies in health Environmental http://whqlibdoc.who.int/hq/1999/WHO_EDM_PAR_99.4.pdf donations for drug Guidelines donations Drug http://www.who.int/immunization/wer8103Diphtheria_Jan06_position_paper.pdf vaccine on diphtheria paper position WHO Diphtheria http://whqlibdoc.who.int/hq/2003/WHO_V&B_03.07.pdf fever (2003) prevention of typhoid and treatment diagnosis, the document: Background http://www.who.int/cholera/publications/cholera_vaccines_emergencies_2005.pdf 14–16 2005) Egypt, December (Cairo, meeting of aWHO Report next? complex what emergencies: in use vaccine cholera Oral http://www.who.int/topics/cholera/publications/shigellosis/ type 1 type rd Communicable disease epidemiological profile epidemiological disease Communicable ed., incorporating 1 incorporating ed., st addendum)

221 IV III II I ANNEXES 222 CENTRAL AFRICAN REPUBLIC AND CHAD http://www.who.int/foodsafety/publications/micro/pif2007/en/index.html (WHO,2007) formula of powdered infant handling and storage preparation, safe for the Guideline http://www.who.int/foodsafety/consumer/5keys/en/index.html handlers food and to consumers advice simple food: to safer Five keys http://www.who.int/foodsafety/foodborne_disease/emergency/en/ disasters natural of aftermath the in safety food Ensuring outbreaks disease safety/Foodborne Food http://www.healthcarewaste.org/en/documents.html?id=184&suivant=25 emergencies in waste of health-care management sound for the steps Four Communicable disease epidemiological profile epidemiological disease Communicable http://www.who.int/3by5/publications/documents/iasc/en/ guidelines Committee Standing Interagency settings: emergency for HIV/AIDS in interventions Guidelines HIV/AIDS http://www.who.int/mediacentre/factsheets/fs280/en/ http://www.who.int/csr/disease/hepatitis/whocdscsredc200112/en/ E Hepatitis http://www.who.int/csr/disease/hepatitis/whocdscsredc2007/en/ A Hepatitis Hepatitis http://www.who.int/reproductive-health/publications/clinical_mngt_rapesurvivors/ ed.) revised 2004, (WHO/UNHCR, persons displaced internally and management of developing rape Clinical protocols survivors: for use refugees with %20(Feb%202007).pdf http://www.humanitarianinfo.org/iasc/content/documents/subsidi/tf_gender/IASC%20Gender%20Handbook (2006) opportunities equal – needs different men and boys women, girls, action: humanitarian in gender handbook IASC http://www.humanitarianinfo.org/iasc/content/products/docs/tfgender_GBVGuidelines2005.pdf (2005) settings humanitarian in interventions for violence gender-based guidelines IASC violence gender-based and Gender http://www.who.int/foodsafety/publications/foodborne_disease/fdbmanual/en/ control and for investigation Guidelines outbreaks: disease Foodborne http://www.who.int/diseasecontrol_emergencies/WHO_HSE_EPR_DCE_2008_3web.pdf (2 populations displaced and in refugee mitigation and preparedness influenza Pandemic http://www.who.int/topics/avian_influenza/en/ influenza Avian Influenza http://whqlibdoc.who.int/publications/2007/9789241595568_eng.pdf facilities health in counselling and testing HIV on provider-initiated Guidance http://whqlibdoc.who.int/publications/2006/9789241594370.cb_eng.pdf settings HIV forIMCI high http://www.who.int/malaria/docs/TreatmentGuidelines2006.pdf of malaria treatment for the Guidelines Malaria http://www.who.int/leishmaniasis/en/ http://www.who.int/leishmaniasis/disease_epidemiology/en/index.html epidemiology and its disease The Leishmaniasis http://www.who.int/csr/resources/publications/surveillance/WHO_CDS_CSR_EDC_2000_4/en/ (2002) outbreaks of investigation field during specimens of clinical collection for the Guidelines Laboratory-specimen collection http://www.who.int/diseasecontrol_emergencies/training/influenza/en/index.html (WHO/CDS/NTD/DCE/2006.2) (2006) agencies for humanitarian modules training WHO populations: displaced and in refugee mitigation and preparedness influenza Pandemic http://www.who.int/diseasecontrol_emergencies/HSE_EPR_DCE_2008_3rweb.pdf settings.) displaced and in refugee field-tested and developed been also has guidelines, these complementing staff, essential to all coordinators health agency by for delivery designed manual (A training (WHO/HSE/EPR/DCE/2008.3) 2008) (revised agencies for humanitarian guidelines WHO populations: displaced and in refugee mitigation and preparedness influenza Pandemic http://www.who.int/csr/disease/influenza/pipguidance2009/en/index.html 2009) (April document andguidance response .WHO preparedness influenza Pandemic nd ed., May 2008) ed., Communicable disease epidemiological profile epidemiological disease Communicable

223 IV III II I ANNEXES 224 CENTRAL AFRICAN REPUBLIC AND CHAD http://whqlibdoc.who.int/publications/2000/9241545208.pdf major in emergencies (2000) of management nutrition The http://www.who.int/diseasecontrol_emergencies/guidelines/Severe_food_shortages.pdf (2005) situations shortage food severe and diseases Communicable http://www.who.int/nutrition/publications/nut_emergencies/en/ publications emergencies in Nutrition Malnutrition http://www.who.int/malaria/docs/ce_interagencyfhbook.pdf (2005) handbook field inter-agency An complex emergencies. in control Malaria Communicable disease epidemiological profile epidemiological disease Communicable http://whqlibdoc.who.int/hq/2004/WHO_V&B_04.03.pdf (WHO/UNICEF) emergencies in mortality measles Joint on statement reducing Measles http://www.paho.org/english/DD/PED/DeadBodiesBook.pdf (2004) situations disaster in bodies of dead Management http://www.paho.org/english/dd/ped/DeadBodiesFieldManual.pdf Management of a disasters: dead after fieldbodies manual for first responders (2006) bodies ofManagement dead http://www.ennonline.net/pool/files/ife/ops-guidance-2-1-english-010307.pdf 2007) (IFE, managers and programme staff relief gency for emer guidance operational emergencies: in feeding child young and Infant http://www.who.int/nutrition/publications/guiding_principles_feedchildren_emergencies.pdf (2004) emergencies during children young and infants for feeding principles Guiding http://www.who.int/child_adolescent_health/documents/fch_cah_00_1/en/index.html countries developing in level referral at first guidelines malnutrition: or severe infection aserious with child of the Management http://www.who.int/nutrition/topics/comm_based_malnutrition/en/index.html malnutrition of severe management Community-based http://www.who.int/nutrition/publications/guide_inpatient_text.pdf (2003) children malnourished of severely treatment inpatient for the Guidelines http://www.who.int/child_adolescent_health/news/2008/13_05/en/index.html for and relief in China emergencies: workers guidance feeding in Myanmar Infant - http://www.who.int/water_sanitation_health/medicalwaste/emergmedwaste/en/ http://www.who.int/water_sanitation_health/medicalwaste/emergmedwaste/en/ Water, health and sanitation emergencies in waste Medical http://www.who.int/immunization/wer7914measles_April2004_position_paper.pdf paper position vaccine Measles http://www.who.int/mediacentre/factsheets/fs286/en/ sheet fact Measles http://www.who.int/immunization/topics/measles/en/index.html on measles Information http://www.who.int/immunization_monitoring/diseases/poliomyelitis_surveillance/en/index.html for poliomyelitis standards surveillance WHO-recommended Poliomyelitis http://www.who.int/csr/resources/publications/WHO_CDS_2005_28/en/index.html guidelines communication Outbreak communications Outbreak Psychosocial.pdf http://www.humanitarianinfo.org/iasc/content/products/docs/Guidelines%20IASC%20Mental%20Health%20 (2007) settings emergency in support psychosocial and health on mental guidelines IASC http://www.who.int/mental_health/resources/emergencies/en/index.html emergencies in health Mental emergencies in health Mental http://www.who.int/csr/resources/publications/meningitis/whoemcbac983.pdf (2 guidelines practical WHO disease: meningococcal epidemic of Control Meningitis http://www.healthcarewaste.org/en/documents.html?id=184&suivant=8 (2005) emergencies in waste of health-care management sound for the steps Four http://www.healthcarewaste.org/en/documents.html?id=15&suivant=16 (1999)gencies emer after and in pharmaceuticals of unwanted disposal for safe Guidelines Communicable disease epidemiological profile epidemiological disease Communicable nd ed., 1998) 1998) ed.,

225 IV III II I ANNEXES 226 CENTRAL AFRICAN REPUBLIC AND CHAD http://whqlibdoc.who.int/publications/2005/9241592330.pdf 1 type dysenteriae due to Shigella of control epidemics for the Guidelines diseases) diarrhoeal other (see also Shigella http://www.who.int/immunization/topics/wer8004pertussis_Jan_2005.pdf paper position vaccine Pertussis Pertussis http://www.who.int/immunization/wer7828polio_Jul03_position_paper.pdf paper position Polio vaccine Communicable disease epidemiological profile epidemiological disease Communicable http://www.who.int/hpvcentre/Maternal_and_neonatal_tetanus_Seminar.pdf TheLancet in (published tetanus neonatal and Maternal http://www.who.int/immunization/wer8120tetanus_May06_position_paper.pdf immunization Position on tetanus paper http://www.who.int/immunization/documents/ISBN9789241595551/en/index.html tetanus of immunization: basis Immunological http://www.who.int/immunization_monitoring/diseases/MNTE_initiative/en/index.html elimination tetanus neonatal and Maternal tetanus Tetanus/maternal neonatal and http://www.who.int/csr/resources/publications/surveillance/WHO_CDS_CSR_ISR_2000_1/en/ WHO report on global surveillance of epidemic-prone infectious diseases (2000) http://www.who.int/csr/resources/publications/surveillance/whocdscsrisr20012.pdf (2001) teams for assessment guidelines systems: response and surveillance disease communicable of national assessment forProtocol the Surveillance http://www.who.int/surgery/publications/imeesc/en/index.html kit tool (IMEESC) care surgical emergency and essential of management Integrated care Surgery/emergency surgical http://whqlibdoc.who.int/publications/2006/9241547103_eng.pdf helminthiasis human in chemotherapy Preventive helminths Soil-transmitted , December 2007) , December Vaccine-preventable diseases: monitoring system (2007, summary) system monitoring global Vaccine-preventable diseases: http://www.who.int/immunization/en/ biologicals Vaccines and Vaccines http://www.who.int/ith/en/ (2008) health and travel International http://www.who.int/foodsafety/publications/consumer/travellers/en/index.html for food travellers on safe Guide Travel advice http://whqlibdoc.who.int/hq/2006/WHO_CDS_NTD_WHOPES_GCDPP_2006.1_eng.pdf (2006) importance health of public pests and of control vectors for the application their and Pesticides http://www.who.int/malaria/vectorcontrol.html control vector Malaria http://www.who.int/malaria/integratedvectormanagement.html management vector Integrated Vector control http://www.who.int/immunization/documents/WHO_VB_03.01/en/index.html diseases vaccine-preventable of selected for surveillance standards WHO-recommended http://www.who.int/immunization/documents/general/en/index.html series of immunization basis Immunological http://www.who.int/vaccines-documents/ http://www.who.int/immunization/documents/en/ immunization and on vaccines Documents http://www.who.int/immunization/documents/positionpapers/en/index.html on vaccines papers position diseases: vaccine-preventable selected of surveillance for Standards http://www.who.int/immunization_delivery/interventions/en/index.html interventions other with vaccines Linking http://www.who.int/immunization_delivery/en/index.html importance of health public diseases against Immunization http://www.who.int/immunization/documents/WHO_IVB_2007/en/index.html Communicable disease epidemiological profile epidemiological disease Communicable 227 IV III II I ANNEXES 228 CENTRAL AFRICAN REPUBLIC AND CHAD http://www.who.int/surgery/publications/EEEGenericListFormatted%2006.pdf equipment list emergency essential generic WHO http://www.who.int/surgery/publications/BestPracticeGuidelinesonESCinDisasters.pdf situations disaster in care surgical on emergency guidelines practice Best http://www.who.int/surgery/publications/imeesc/en/index.html kit tool (IMEESC) care surgical emergency and essential of management Integrated infection.pdf http://www.who.int/hac/techguidance/tools/Prevention%20and%20management%20of%20wound%20 of infections wound management and Prevention Wounds injuries and Communicable disease epidemiological profile epidemiological disease Communicable http://www.who.int/zoonoses/resources/en/ health public veterinary and Zoonoses Zoonoses http://whqlibdoc.who.int/hq/2004/WHO_IVB_04.08.pdf infection fever of virus yellow monitoring for the Manual http://www.who.int/csr/resources/publications/yellowfev/whoepigen9809.pdf for fever surveillance yellow guidelines District http://www.who.int/vaccines-documents/DocsPDF/www9842.pdf Yellow fever disease Yellow fever

WHO fact sheetsWHO on fact communicable diseases ANNEX 4 Lymphatic filariasis Lymphatic Leprosy safety Injection Influenza E Hepatitis C Hepatitis B Hepatitis emergencies in safety Food illness foodborne and safety Food Ebola Diphtheria Dengue Cholera Anthrax sickness) (sleeping trypanosomiasis African Title Communicable disease epidemiological profile epidemiological disease Communicable index.html http://www.who.int/mediacentre/factsheets/fs102/en/ 2000 September 102, revised http://www.who.int/topics/leprosy/en/ 2005 October 101, revised http://www.who.int/mediacentre/factsheets/fs231/en/ 2006 October 231, revised http://www.who.int/mediacentre/factsheets/fs211/en/ 211, 2003 March index.html http://www.who.int/mediacentre/factsheets/fs280/en/ 2005 January revised 280, http://www.who.int/mediacentre/factsheets/fs164/en/ 2000 October revised 164, http://www.who.int/mediacentre/factsheets/fs204/en/ 2000 October revised 204, emergency/en/ http://www.who.int/foodsafety/foodborne_disease/ http://www.who.int/mediacentre/factsheets/fs237/en/ 2007 March 237, revised http://www.who.int/mediacentre/factsheets/fs103/en/ 2007 September 103, revised http://www.who.int/mediacentre/factsheets/fs089/en/ 2000 December 89, revised http://www.who.int/mediacentre/factsheets/fs117/en/ 117, 2002 April revised http://www.who.int/mediacentre/factsheets/fs107/en 2007 107, September revised http://www.who.int/mediacentre/factsheets/fs264/en/ 2001 October 264, http://www.who.int/mediacentre/factsheets/fs259/en/ 2006 August 259, revised date/URL No./Publication sheet Fact 229 IV III II I ANNEXES 230 CENTRAL AFRICAN REPUBLIC AND CHAD Communicable disease epidemiological profile epidemiological disease Communicable Water, sanitation and health and Water, sanitation fever Yellow Organization Health World Tuberculosis Schistosomiasis (drug-resistant) Salmonella fever Valley Rift Rabies Poliomyelitis Plague Meningitis Measles fever haemorrhagic Marburg Malaria emergencies/envsanfactsheets/en/print.html http://www.who.int/water_sanitation_health/hygiene/ water on sheets fact to Introduction http://www.who.int/mediacentre/factsheets/fs100/en/ 2001 December revised 100, http://www.who.int/about/en/ WHO About http://www.who.int/mediacentre/factsheets/fs104/en/ 2007 March revised 104, http://www.who.int/mediacentre/factsheets/fs115/en/ 2007 July 115, revised index.html http://www.who.int/mediacentre/factsheets/fs139/en/ 2005 April 139, revised print.html http://www.who.int/mediacentre/factsheets/fs207/en/ 2007 September 207, revised http://www.who.int/mediacentre/factsheets/fs099/en/ 2006 November 99, revised http://www.who.int/mediacentre/factsheets/fs114/en/ 2008 January 114, updated http://www.who.int/mediacentre/factsheets/fs267/en/ 2005 February 267, revised http://www.who.int/mediacentre/factsheets/fs141/en/ 2003 May 141, revised http://www.who.int/mediacentre/factsheets/fs286/en/ 2007 November revised 286, fs_marburg/en/index.html http://www.who.int/mediacentre/factsheets/ 2005 March http://www.who.int/mediacentre/factsheets/fs094/en/ 2007 May 94, studies Laboratory viralparasitic examinations) and for required media transport No required Specimens pathogens diseases/ Possible syndrome of Definition outbreak Suspected Flowcharts for the diagnosis of communicable diseases ANNEX 5 refer to “Acute haemorrhagic fever syndrome” for appropriate specimen collection guidelines. collection specimen appropriate for syndrome” fever “Acute to haemorrhagic refer suspected, is etiology an such If diarrhoea. bloody as present initially may fevers haemorrhagic other and Ebola

Toxin identification Faecal leukocytes Antimicrobial susceptibility susceptibility Bacterial: Serotyping Culture Acute onset of diarrhoea and severe illness and illness severe and diarrhoea of onset Acute ACUTE DIARRHOEA ANDACUTE ACUTE DIARRHOEA WATERY DIARRHOEA known predisposing factors predisposing known Communicable disease epidemiological profile epidemiological disease Communicable Enterotoxigenic E. coli Viral gastroenteritis Genome detection Genome Antigen detection Cryptosporidium Giardiasis Cholera Faeces Watery Culture Viral: transport medium transport Cary-Blair In absence of of absence and microscopic examination Macroscopic Parasitic: 231 IV III II I ANNEXES 232 CENTRAL AFRICAN REPUBLIC AND CHAD studies Laboratory examinations) viral parasitic for required and media (No transport media transport and required Specimen pathogens diseases/ Possible syndrome of Definition outbreak Suspected Communicable disease epidemiological profile epidemiological disease Communicable guidelines. collection specimen appropriate for syndrome” fever “Acute to haemorrhagic refer suspected, is etiology an such If diarrhoea. bloody as present initially may fevers haemorrhagic other and Ebola

Toxin identification Faecal leukocytes Antimicrobial susceptibility Bacterial: Serotyping Gram stain Culture Acute onsetofdiarrhoeaandsevere illnessandabsence of ACUTE BLOODY DIARRHOEA known predisposing factors Enterohaemorrhagic E. coli Haemorrhagic fevers Campylobacteriosis Amoebic dysentery Clostridium difficile Genome detection Genome Antigen detection Salmonellosis Shigellosis Faeces Culture Viral: gerate at 2–8 °C 2–8 at gerate Shigella, for medium; port trans Cary-Blair and microscopic examination Macroscopic Parasitic: refri - - studies Laboratory required Specimens pathogens diseases/ Possible syndrome of Definition outbreak Suspected

Other arboviralOther haemorrhagicfevers (e.g. Rift Valley, Crimean–Congo, Postmortem tissuespecimens(e.g. skin and/orliver biopsy) Acute onsetoffever oflessthan3weeks’ duration andany two Genome detection Genome Antigen detection Antibody levels Haemorrhagic fever withrenal syndrome (hantaviruses) Lassa fever andotherarenoviral haemorrhagicfevers Culture Dengue haemorrhagicfeverDengue andshocksyndrome Viral: ACUTE HAEMORRHAGIC SYNDROME FEVER and absence ofknown predisposing factors. Ebola orMarburg haemorrhagicfevers

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Yellow fever blood instool haemoptysis

Malaria Serum Blood epistaxis Demonstration ofpathogen Parasitic: 233 IV III II I ANNEXES 234 CENTRAL AFRICAN REPUBLIC AND CHAD studies Laboratory required Specimens pathogens diseases/ Possible syndrome of Definition outbreak Suspected Communicable disease epidemiological profile epidemiological disease Communicable * Requires specialized media and handling procedures. handling and media specialized Requires

Postmortem liver biopsy Yellow fever Antigen detection Genome analysis Genome Antibody levels Acute onsetofjaundice andsevere illnessandabsence of Culture Viral: ACUTE JAUNDICE SYNDROME known predisposing factors Hepatitis A–E Serum Antibody levels Leptospiral: Serotyping Culture other spirochaetal Leptospirosis and (urine*) diseases Blood syndrome of Definition outbreak Suspected Laboratory studies Laboratory required Specimens pathogens diseases/ Possible Culture Viral:

microscopic techniques Gram stain andother Antigen detection Poliomyelitis or Guillain–Barré leptospiral): Antimicrobial susceptibility susceptibility (including Serotyping Bacterial syndrome Faeces Culture Acute withoneormore neurological ofthefollowing: dysfunction and severe illnessandabsence ofpredisposing factors. ACUTE NEUROLOGICAL SYNDROME

Communicable disease epidemiological profile epidemiological disease Communicable deterioration ofmental function

other neurological symptoms signs ofmeningealirritation

Viral, bacterial, fungal Lymph nodeaspirate involuntary movements Blood concentrationBlood or parasitic menin - CSF concentration Parasitological Blood smears

goencephalitis Throat swab

acute paralysis methods methods convulsions Lymph Serum Blood (HAT) CSF Postmortem speci- impressions, brain mens (e.g. corneal tissue, skin biopsy Antigen detection Genome analysis Genome Antibody levels from neck) Culture Serum Rabies Viral: 235 IV III II I ANNEXES 236 CENTRAL AFRICAN REPUBLIC AND CHAD outbreak Suspected Communicable disease epidemiological profile epidemiological disease Communicable from: Adapted studies Laboratory required Specimens syndrome of Definition WHO, 2000 (WHO/CDS/CSR/EDC/2000.4). 2000 WHO, pathogens diseases/ Possible Throat swab Streptococcal Scarlet feverScarlet pharyngitis Diphtheria Influenza

Guidelines for the collection of clinical specimens during field investigation of outbreaks. outbreaks. of investigation field during specimens clinical of collection the for Guidelines pulmonary pulmonary Hantavirus Acute onsetofcough orrespiratory distress and severeand illness syndrome Antimicrobial (for bacteria) susceptibility Serum Bacterial orviral: Bacterial Toxin identification Antigen detection Genome analysis Genome Antibody levels absence ofknown predisposing factors Serotyping Culture ACUTE RESPIRATORY SYNDROME Nasopharyngeal Nasopharyngeal syncytial virus syncytial Respiratory Respiratory Pertussis (RSV) (RSV) swab Pneumonic plague Bacterial pneumo Bacterial Blood culture Pneumococcal nia, including: Legionellosis Haemophilus Mycoplasma Respiratory Respiratory Legionella) Urine (for influenzae Sputum anthrax Serum Geneva, Geneva, -