WHO Library Cataloguing in Publication Data Contents WHO Regional Office for the Eastern Mediterranean Integrated vector management: strategic framework for the Eastern Mediterranean Region 2004-2010 / WHO Regional Office for Foreword by the Regional Director 4 the Eastern Mediterranean. p. Message from the Director, 5 ISBN 92-9021-340-0 Division of Communicable Disease 1. Communicable diseases control 2. Disease vectors Control 3. Developing countries 4. Eastern Mediterranean Region I. Title Introduction 6 [NLM Classification: WC 100] Vector control interventions 8
Reasons for employing integrated 9 Permission to use photographs from the TDR Image Library, WHO vector management headquarters, is gratefully acknowledged. The following photographs are credited: Page 17 top and bottom photos by Andy Crump, Page 18 photo by Tony Ward, Page 21 top photo by Dr Mike Nathan. Justification and guiding principles 10
Institutional justification 10 © World Health Organization 2004 Technical justification 10 All rights reserved. The designations employed and the presentation of the material in Guiding principles for the 11 this publication do not imply the expression of any opinion whatsoever development and implementation on the part of the World Health Organization concerning the legal of IVM interventions status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. Objectives of the strategic 12 framework The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the Priority actions for 13 names of proprietary products are distinguished by initial capital implementation of integrated letters. vector management Thee World Health Organization does not warrant that the information contained in this publication is complete and correct and shall not be liable for any damages incurred as a result of its use. Targets for implementation of 14 Publications of the World Health Organization can be obtained from integrated vector management Distribution and Sales, World Health Organization, Regional Office for the Eastern Mediterranean, PO Box 7608, Nasr City, Cairo 11371, Role of Member States 14 Egypt (tel: +202 670 2535, fax: +202 670 2492; email: [email protected]). Requests for permission to reproduce WHO EMRO publications, in part or in whole, or to translate them – Role of WHO 15 whether for sale or for noncommercial distribution – should be addressed to the Regional Adviser, Health and Biomedical Information, Annexes 16 at the above address (fax: +202 276 5400; email [email protected]. 1. Regional distribution and burden 16 of vector-borne diseases 2. Terminology and definitions 24 programmes, initially developed to target malaria vectors but found also to have an Message from the Director, impact on other vector-borne diseases such as leishmaniasis. Communicable Disease Control The Division of Communicable Disease In the past such programmes were Control in the WHO Regional Office for the implemented exclusively through the vertical Eastern Mediterranean strongly believes in structures of ministries of health. However, the best utilization of available resources, the time has come to take advantage of the interventions and services at all levels of potential to target vector-borne diseases health care delivery. It is for this reason that through intersectoral action for health. To do the Divison is actively promoting integrated this, we must harness the existing high levels disease management as a cornerstone of of political commitment in countries of the regional and national strategies to control Region to enhance intersectoral collaboration. communicable diseases. We also encourage countries to use the available tools to maximize the impact of Well-planned and coordinated vector control each intervention with a view to reducing interventions contribute significantly to vector-borne disease risks. Since such tools reduction of the incidence of vector-borne will inevitably include, for the time being, diseases. Effective vector control methods the use of insecticides, the protection of exist, but their implementation as part of to finance, distribute and target insecticide- human health and the environment must be integrated disease management is limited. treated bednets (ITNs) equitably in order to our prime concern. The potential to use one or several of these ensure high coverage rates for the reduction interventions to address more than one vector- in the incidence of vector-borne diseases in The Regional Strategic Framework for borne disease exists and should be promoted. countries of the Region. Such methods will Integrated Vector Management has come at There is also a need to scale up some of these Foreword by the inevitably have to rely on meaningful an opportune moment. It provides long-range interventions in a cost-effective manner. For public–private partnerships, including Regional Director vision and guidance for planning and example, realistic methods must be sought undertaking vector control activities in untapped community resources. countries of the Eastern Mediterranean Region Vector-borne diseases are a significant source in the coming years. It once again reflects The process of developing the Regional of morbidity and mortality in the WHO our continued commitment, and that of our Strategic Framework for Integrated Vector Eastern Mediterranean Region, which suffers partners, to addressing the control of vector- Management (IVM) involved a series of a disproportionate share of the global burden borne diseases in a sustainable and cost- correspondence with international experts, of vector-borne disease. The distribution of effective manner. relevant national representatives and partners. such diseases, and their burden, varies greatly This process was followed by an intercountry within and between the countries of the meeting in Khartoum, Sudan in January 2003, Region. in which a draft strategy was reviewed and finalized. It is in the same spirit of The situation is further complicated by the inclusiveness and openness that countries are emergence and potential spread of insect- Hussein A. Gezairy expected to make use of this important policy borne arboviruses. The Region has also seen MD, FRCS framework to develop national IVM plans of considerable success with vector control action that reflect existing local situations.
4 5 from the vector-borne disease burden and its The Eastern Mediterranean Region comprises various zoogeographical zones, Afrotropical, Introduction socioeconomic consequences. Oriental and Palaearctic (Figure 1). Each of these zones has a specific cluster of dominant vector species. At the margins of their distribution within each zone, vector populations may As detailed in Annex 1, the most important be less stable and therefore easily controlled by vector control interventions; however, at the vector-borne diseases harming human health core of their distribution area, they are likely to be well-entrenched and will require a more in the Region are malaria and lymphatic powerful package of interventions to control them to a degree sufficient to have a significant filariasis transmitted by mosquitoes, impact on transmission risk. Within each zone, different species will have different ecological leishmaniases transmitted by sandflies, requirements. Knowledge of these requirements is fundamental to the development of integrated schistosomiasis from aquatic snails and vector management, which bases itself on an ecosystems approach. An imbalance, caused by diarrhoeal diseases and trachoma transmitted extreme weather conditions, floods or drought, or by human actions that change the hydrology by flies. Also present, but of more limited or land-use patterns, can lead to explosive increases in vector populations with dire consequences importance as vector-borne diseases, are for vector-borne disease transmission risks. Chemical interventions in agro-ecosystems, for trypanosomiasis carried by tsetse flies, example, can have similar adverse impacts. Strategies aimed at reducing disease transmission onchocerciasis carried by blackflies and while maintaining or restoring ecosystem integrity are therefore needed. several mosquito-borne arboviruses: notably Rift Valley fever, dengue and Crimean–Congo haemorrhagic fever. The potential for spread of West Nile fever and yellow fever in the Palaearctic Region is very high. Other arthropod pests and potential vectors include fleas, ticks, cockroaches and rodents of many species. These pests, vectors and vector-borne diseases are unevenly distributed within the Region and have patchy foci within individual Oriental Background countries. The dynamics of vector Afrotropical populations, the level of transmission risks Globally, vector-borne diseases are and the incidence of diseases fluctuate responsible for almost 20% of the estimated seasonally. burden of infectious diseases affecting humanity, largely due to malaria and other The everyday reality of this widespread parasitic diseases in developing countries. In burden makes the control of vector-borne Figure 1. Zoogeographical zones in the Eastern Mediterranean Region the 22 countries of the WHO Eastern disease a key component of health sector Mediterranean Region, vector-borne diseases activities to protect and promote health. contribute to over 2% of the total estimated Moreover, due to the complexities of ecology, burden of disease. While 8% of the world epidemiology and risks of exposure, these population lives in the Region (2001), almost diseases are particularly important targets for 11% of the global burden of vector-borne intersectoral action for health. diseases is found here (Annex 1). Regionally, vector-borne diseases represent about 17% of the burden of all infectious disease and are disproportionately distributed to only a few countries. These countries suffer most 6 7 Bacterial larvicides are preferred because coordinating and re-focusing pre-existing they specifically control mosquito larvae, resources for IVM against multiple vectors, whereas chemical larvicides also affect a through both intersectoral and intrasectoral wider range of non-target organisms. More cooperation to maximize benefits and cost- attention should be given to cost–effectiveness efficient use of available resources; analysis of vector control operations to ensure the most judicious and beneficial application using alternate and/or multiple interventions, of insecticides and other potential so as to reduce dependence on the use of interventions. pesticides; One of the problems countries are facing is achieving sustainable long-term prevention the limited choice of safe insecticides because of vector-borne diseases at minimal cost. of widespread insecticide resistance. In most countries of the Region, resistance has been In the short term, IVM should multiply the reported in several vectors, apparently impact of individual interventions to achieve resulting from exposure to agricultural critical reduction of risks. This may mean insecticide usage in some cases. More effort that the resources required for IVM are greater is needed to monitor the extent and effects than for any single intervention, but if properly of insecticide resistance using the latest implemented the effectiveness of interrupting methods and criteria. Reasons for employing integrated vector management transmission through IVM will be proportionally greater than the increase in For vector control programmes, guidance is overall costs. needed for countries to show how, what, when, and where, each precaution and The key reason for employing an IVM In the long term, IVM should also help to Vector control interventions intervention should be selected and used; strategy is to strengthen impact through prevent and overcome costly setbacks, such especially the synergies that may be derived complementary methods of vector control as those that may arise due to changes of Historically the main vector control measures from combining several methods. Merging with operational flexibility, while respecting vector behaviour or development of in the majority of countries in the Region different control programmes is a priority so ecosystem integrity. Ideally IVM should insecticide resistance. have been indoor residual spraying and larval that more than one vector-borne disease can reduce vectorial capacity (Annex 2) to the control using insecticides and larvivorous be jointly targeted where the vectors occur point of preventing transmission risks. IVM fish. These interventions, combined with together and have similar behaviour or programmes usually involve: environmental management and improved ecology (Annex 1). The strategic framework housing, have reduced and eliminated malaria for integrated vector management has been carrying out a sound ecosystem and eco- and, incidentally, other vector-borne diseases developed to provide the necessary guidance epidemiological analysis to reveal the critical in most countries. to countries. points in disease transmission that can be targeted for maximum impact on disease During the past decade, insecticide-treated interruption; nets (ITNs) have been introduced for protection against the transmission of malaria designing a series of incremental and leishmaniasis. Space spraying is part of interventions, whereby each additional the vector control programmes in some intervention yields maximum health gains at countries, but is often over-employed. the least additional cost;
8 9 on insecticides for control of vector-borne Justification and diseases through promotion of integrated pest IVM should be economically feasible, cost- guiding principles management approaches. It also called upon effective, sustainable, environmentally sound them to ensure that the use of and socially acceptable. dichlorodiphenyltrichloroethane (DDT) is authorized by governments for public health Vector control interventions are components purposes only, and that such use is limited of integrated vector-borne disease control to government-authorized programmes that programmes, which are in line with national take an integrated approach. health sector reform.
During an informal consultation on the Wherever and whenever possible, vector integrated approach to control communicable control interventions should be planned for diseases in 2002, the Division of multiple vector-borne disease prevention and Communicable Diseases in the Regional control. Office for the Eastern Mediterranean Regional adopted IVM as one of its strategies to control Incentives and regulatory or institutional communicable diseases. arrangements need to be designed and employed to ensure effective intersectoral collaboration.
Programme management can be optimized Technical justification by enabling decision-making at local levels. The IVM approach builds on the concept of This should be considered in the context of Well-planned and coordinated vector control selective vector control with the targeted use health sector decentralization and the need Institutional justification interventions can help reduce the incidence of different vector control methods, alone or for active community participation. and burden of vector-borne disease. Although in combination, to prevent or reduce In 1989, the World Health Assembly issued effective vector control methods exist, in the human–vector contact. In addition, IVM resolution WHA 42.31, which urged Member past they have only addressed one disease at should be cost-effective and sustainable, States to reinforce capacity so that effective a time, so that their implementation as part involve intersectoral cooperation and have vector control measures are taken for the of integrated disease management packages no adverse side effects for people or the control of disease vectors, and to develop has been limited. environment. and maintain adequate human resources for this purpose. The Director-General is In many countries, decentralization is requested to ensure that input in the providing opportunities for vector control development of safe and effective methods with community participation, using focal Guiding principles for the for the control of disease vectors continues persons at the community level and outreach development and to be based on sound ecological services to implement IVM. Limited financial implementation of IVM considerations, in accordance with the resources of vector-borne disease control principles of sustainable development. programmes and the limited number of safe, interventions cost-effective pesticides require selective and Resolution WHA 50.13 (1997) called upon careful application of pesticides within IVM is an essential element of vector-borne Member States take steps to reduce reliance integrated vector management. disease control. 10 11 The general objective of the strategic framework for IVM is to provide countries Priority actions for implementation of of the Region with guidance on the optimal use of resources (financial, human and integrated vector management technical, including insecticides) for IVM programmes. Using the strategic framework, Incorporating IVM principles into national Promoting intersectoral and intrasectoral each country is expected to prepare, adopt health policies. cooperation to optimize allocation of and implement a national plan of action for resources within the health sector (e.g. IVM by 2004. Strengthening vector control capability within environmental health and different vector- the national health system. borne disease programmes) and intersectoral Specific objectives of the framework are to: collaboration between different government Establishing or strengthening national sectors, (especially agriculture, environment promote regional implementation of IVM capacity to implement IVM, including and local government/municipalities) principles providing training, promoting career supported by appropriate policies, legislation opportunities, enhancing collaboration, and impact assessment. promote efficient allocation of resources to guiding re-orientation of vector control vector control activities and ensuring availability of skilled Establishing partnerships to mobilize public staff. and private sectors, together with civil society, foster strengthening of the capacity for IVM nongovernmental organizations and donors, Engaging in advocacy to ensure political to optimize allocation of resources and ensure promote the use of non-chemical vector commitment for IVM as an important effective implementation of IVM. control interventions and appropriate component of communicable disease control management of pesticides (CDC), and developing policies and Monitoring and evaluating ongoing vector legislation to increase community control activities by employing entomological promote integrated disease control participation, empowerment and mobilization surveillance and conducting operational Objectives of the of human and financial resources. research, including post-registration strategic promote intersectoral and intrasectoral monitoring of pesticide use. collaboration and partnership, including framework community participation.
The aim is for all countries of the Region to adopt and implement well integrated and cost-effective programmes for vector management and control in order to prevent, reduce or interrupt transmission of vector- borne diseases and prevent the re- establishment of local transmission.
12 13 Role of Member States Role of WHO
Depending on the situation in each country, To assist countries in fulfilling the targets effective implementation of IVM will require listed above, WHO will: the establishment, strengthening or re- organization of vector control services to 1. Finalize and disseminate the draft regional facilitate multidisciplinary and intersectoral strategic framework among Member States collaboration. The first step for all countries for comments and suggestions (by June 2003). is implementation of a comprehensive needs assessment, to be used as a basis for fulfilling 2. Obtain endorsement of the regional strategic the following targets: framework from the Regional Committee for the Eastern Mediterranean in 2003. Identification of the technical, human and financial resources or deficiencies for the 3. Prepare and disseminate technical guidelines implementation of IVM activities. for conducting the situation analysis and needs assessment of IVM activities (by the Development of a proposal for the end of 2003). establishment of IVM services within the existing framework of national health policies 4. Develop and disseminate technical guidelines and health systems, and reaching an for the planning, implementation, monitoring agreement with relevant authorities. and evaluation of vector control interventions based on integrated vector management for Establishment or strengthening of a structure communicable disease control (2004). for the planning, implementation, monitoring Targets for and evaluation of an IVM programme. A core 5. Provide the necessary technical support for group will guide, support and when necessary, Member States to conduct situation analyses, implementation participate in IVM activities. needs assessment, planning, implementation, monitoring and evaluation of vector control of integrated Development of national guidelines for the interventions based on the IVM approach. vector planning, implementation, monitoring and management evaluation of IVM activities. Establishment of mechanisms to ensure intersectoral and intrasectoral collaboration, public–private partnership, cross-border coordination and community participation.
Planning and carrying out of operational research for evidence-based IVM interventions.
14 15 Annex 1 Regional distribution of vector- Lymphatic filariasis borne diseases Caused by the nematode Wuchereria bancrofti transmitted by mosquitoes. Extreme Major vector-borne diseases symptoms are known as elephantiasis. As transmission of the microfilariae requires high humidity, distribution is limited by the Malaria generally arid climate of the Region. Foci Caused by human infection with Plasmodium include the Nile delta of Egypt and probably falciparum and P. vivax. Anopheline mosquito the Republic of Yemen. Transmission is by vectors of malaria are present in all mosquitoes of the Culex pipiens complex. 22 countries of the Region. Even so, malaria Lymphatic filariasis across southern Sudan transmission has been effectively interrupted is transmitted by anopheline mosquito vectors, in 9 countries (Bahrain, Egypt, Kuwait, as for malaria. There is a potential risk that Lebanon, Libyan Arab Jamahiriya, Oman, expanding practices of wastewater re-use for Qatar, Tunisia, United Arab Emirates). Active agriculture may lead to the increased malaria transmission continues in at least the Leishmaniasis propagation of Culex vectors and an following countries: Afghanistan, Islamic Caused by Leishmania protozoa transmitted intensification of transmission of the disease. Republic of Iran and Pakistan due to by phlebotomine sandflies. Three forms of transmission mainly by Anopheles culicifacies leishmaniasis affect this Region, namely: Schistosomiasis and An. stephensi; Djibouti, Saudi Arabia, visceral (VL due to L. donovani in Sudan Caused by trematode worms. Schistosoma Somalia, Sudan and the Republic of Yemen and widespread L. infantum), zoonotic haematobium causes urinary bilharzia and S. due to transmission mainly by An. arabiensis; cutaneous (ZCL due to L. major) and mansoni causes intestinal bilharzia. The latter Iraq and the Syrian Arab Republic due to anthroponotic cutaneous (ACL due to L. occurs in Egypt, Oman, Saudi Arabia, Sudan, Regional transmission by An. sacharovi and other tropica). These diseases have focal vectors. Due to the widespread prevalence distribution in the Islamic Republic of Iran, distribution and of competent vectors, most parts of the Region Iraq, Sudan, Syrian Arab Republic and Tunisia remain vulnerable and receptive to malaria. and cause important public health problems burden of vector- Irrigation schemes and other water resources in Afghanistan and Pakistan. Leishmaniasis borne diseases projects provide conditions for malaria in is a lesser problem in Djibouti, Jordan, what is otherwise a semi-arid to arid region Kuwait, Lebanon, Libyan Arab Jamahiriya, and therefore become foci of intense Morocco, Oman, Saudi Arabia, Somalia and transmission. the Republic of Yemen. There are more than 20 vector species of Phlebotomus in the Region, with obscure breeding sites. The most widespread and important are P. papatasi as vector of L. major; P. sergenti as vector of L. tropica; P. perniciosus as vector of L. infantum and P. orientalis as vector of L. donovani.
16 17 Republic of Yemen, whereas S. haematobium intermediate copepod hosts (Cyclops). It was probably widespread, little recent information is more widespread across North Africa and formerly endemic across Africa and Asia, but is available on their distributions in each the Arabian peninsula. Intermediate hosts are is now limited to foci in several tropical country. aquatic snails of the genus Bulinus for S. African countries, mostly in Sudan. haematobium and Biomphalaria for S. Scrub typhus mansoni living in marshes and irrigation Trypanosomiasis (sleeping sickness) Caused by the zoonotic bacterium Rickettsia systems where infection is acquired when Caused by trypanosomes transmitted by tsetse tsutsugamushi transmitted by trombiculid people bathe or work in infested waters. flies (Glossina). Also mostly a disease of mites, is zoonotic across South-east Asia. In tropical Africa, transmission extends across Pakistan the vector is Leptotrombidium deliae. Trachoma southern Sudan. Due to the economic Caused by Chlamydia trachomatis bacterial importance of trypanosomiasis affecting Diarrhoeal diseases infection of the eyes, transmitted mostly by livestock, a continent-wide campaign is taking Caused by enteric bacteria (e.g. E. coli O157, flies Musca sorbens. This occurs in most shape: the Pan African Tsetse and Salmonella, Shigella) and viruses are partly countries of the Region, but has been poorly Trypanosomiasis Eradication Campaign. transmitted by houseflies, blowflies, face- mapped. flies and cockroaches, widespread throughout Borrelioses the Region. The main transmission pathway Vector-borne diseases of lesser or Due to spirochetes transmitted by several is via direct faecal–oral transmission. more local importance types of ectoparasites: body lice (Pediculus humanus) vectors of Borrelia duttoni causing Plague louse-borne relapsing fever (LBRF); soft Caused by Yersinia pestis bacteria transmitted Onchocerciasis (river blindness) ticks (Ornithodoros) vectors of Borrelia by Xenopsylla fleas. Scattered foci of enzootic Caused by the filarial nematode Onchocerca recurrentis causing tick-borne relapsing fever plague exist across the Region, with human volvulus, transmitted by blackflies of the (TBRF); hard ticks (Ixodidae) carrying cases of zoonotic origin recorded occasionally Simulium damnosum group that breed in fast- Borrelia burgdorferi causing Lyme disease. in Iraq, Islamic Republic of Iran, Libyan Arab flowing waterways. Largely a disease of While these arthropods and infections are Jamahiriya, Morocco, Saudi Arabia and tropical Africa, two countries of the Region Tunisia. have endemic onchocerciasis. The Republic of Yemen harbours small foci in a few highland valleys, while Sudan has foci along several river systems.
Loiasis (Calabar swelling) Caused by the filarial nematode Loa loa, transmitted by Chrysops flies breeding in muddy areas. The disease is associated with rainforests of tropical Africa and endemic across southern Sudan.
Guinea-worm (dracunculiasis) Caused by nematode Dracunculus medinensi. Ingested with drinking water via the 18 19 public health problems if the epidemic is not Yellow fever contained. Causes very severe fever and jaundice with a high mortality rate. In tropical Africa, the Dengue sylvatic cycle of yellow fever involves Causes dengue fever with mild transient monkeys and various aedine mosquito symptoms, sometimes progressing to dengue vectors, with Aedes simpsoni and other link haemorrhagic fever or dengue shock vectors to villages. Urban epidemics are syndrome. No dengue vaccine is available. vectored by Aedes aegypti with human-to- Dengue viruses are transmitted by Aedes human transmission, as for dengue. (Stegomyia) aegypti, which is very Vaccination is very effective and compulsory anthropophilic and breeds in domestic water for international travellers from countries containers. Another vector spreading around such as Sudan and Somalia that lie in the the Mediterranean is Aedes (Stegomyia) infection zone of yellow fever. albopictus, raising the likelihood of dengue outbreaks. Recurrent major epidemics of Rift Valley fever dengue occur across tropical Asia and the Transmitted mostly by various Culex spp. Arboviruses transmitted by other Americas, but so far dengue remains during epidemics and carried through dry arthropods in the Region uncommon in the Eastern Mediterranean seasons in dormant eggs of Aedes mosquitoes Region. Cases of dengue have been reported (vertical transovarial transmission) from from Pakistan, Saudi Arabia, Somalia and which the resultant females become infective Crimean–Congo haemorrhagic fever Sudan and recently from Djibouti and the and transmit to amplifier hosts at the start of Transmitted by ixodid ticks (mainly Republic of Yemen. the next rainy season. No vaccine is available. Hyalomma) and carried by livestock (goats Serious outbreaks have occurred recently in and sheep). It has spread to Afghanistan, Japanese encephalitis Islamic Republic of Iran, Iraq and Pakistan. Typhus Somalia, Saudi Arabia and the Republic of Transmitted by many types of mosquitoes, Cases are reported annually with localized Caused by zoonotic bacteria of three types: Yemen, causing large-scale mortality of especially Culex spp. breeding in irrigated outbreaks from these countries. louse-borne Rickettsia prowazeki causing livestock and some human deaths. rice fields. Japanese encephalitis virus is classical typhus, transmitted by Pediculus disseminated by egrets and other birds Sandfly fever humanus; flea-borne Rickettsia typhi causing West Nile fever associated with irrigation and marshland. Causes mild symptoms in humans due to murine typhus, transmitted by various species Transmitted by many types of mosquitoes, Amplifier hosts include domestic livestock, of fleas; tick-borne R. conori causing mostly Culex spp. West Nile is disseminated zoonotic phlebovirus and is carried by rodents especially pigs. Fortunately Japanese boutonneuse fever transmitted by by birds, which often die. Amplifier hosts and transmitted by various phlebotomine encephalitis vaccines are available: children Haemaphysalis ticks. include horses that often die. Human sandflies. It is widespread in most countries and pigs are routinely vaccinated in some symptoms vary from mild fever to serious of the Region. countries. Cases have been reported in the complications with significant mortality rate. Arboviruses transmitted by Indus valley of Pakistan and suspected in mosquitoes Afghanistan, but the incidence remains No vaccine is available. West Nile outbreaks occur frequently around the Mediterranean Arboviruses (arthropod-borne viruses) of unclear in the Eastern Mediterranean Region. but none of the countries of the Region have many types are widespread zoonoses, mostly As the principal vector Culex officially reported cases. The potential for transmitted by quite specific vectors. Sporadic tritaeniorhynchus is widespread from outbreaks are difficult to foresee and usually Southeast Asia to West Africa, further spread outbreaks exists in Egypt, Jordan, Morocco, pass quickly, for ecological and of Japanese encephalitis across the Region Palestine and Tunisia. epidemiological reasons. Some cause serious is a real possibility. 20 21 Other potential vectors occurring in most, Burden of vector-borne diseases in the Eastern Mediterranean probably all, countries of the Region include Region biting midges (Culicoides, Leptoconops), stable flies (Stomoxys), horseflies (Tabanidae) Ten vector-borne diseases are sufficiently prevalent in the Region to be listed in The world and hard ticks (Ixodidae), which occasionally health report 2002 as significant contributors to the burden of disease (Table 1). transmit the bacterium Francisella tularensis Table 1. Estimated disability-adjusted life-years (DALYs) lost in 2001 in countries of the causing tularaemia. Larvae of some larger Eastern Mediterranean Region due to infections from selected vector-borne diseases flies (e.g. Chrysomya, Lucilia, Wohlfahrtia) cause myiasis when they invade human flesh Vector-borne Burden in Endemic Epidemic- Non-endemic (by burrowing) or intestines (by ingestion). disease DALYs* prone Despite much speculation and conjecture, all Diarrhoeal diseases** 10 784 000 All All 0 evidence indicates that blood-sucking insects Malaria 2 050 000 Afghanistan, All 17 countries cannot transmit HIV/AIDS. Conversely, there Djibouti, Somalia, Sudan, Republic of is some experimental evidence for Yemen
transmission of hepatitis B virus by bedbugs Trachoma 602 000 Afghanistan, – Bahrain, Jordan, (Cimex), although epidemiological evidence Djibouti, Egypt, Kuwait, Lebanon, Iraq, Islamic Palestine, Qatar, indicates no significant role of bedbugs as Republic of Iran, Saudi Arabia, Libyan Arab Syrian Arab vectors of any infection. Jamahiriya, Republic, Tunisia Morocco, Oman, Pakistan, Somalia, Rodents are carriers of haemorrhagic fever Sudan, United Arab Emirates, Republic viruses, poorly known in this Region, and of Yemen other zoonotic infections such as leptospirosis Lymphatic filariasis 489 000 Egypt, Sudan, – 19 countries and those mentioned above, i.e. Lyme disease, Republic of Yemen typhus and plague. Leishmaniasis 278 000 17 countries Afghanistan, Bahrain, Djibouti, Pakistan, Sudan Kuwait, Qatar, United Arab Extensive and largely successful vector Emirates control programmes have influenced the Schistosomiasis 202 000 Egypt, Iraq, Jordan, Libyan Afghanistan, distribution patterns and prevalence of vectors Morocco, Saudi Arab Jamahiriya, Bahrain, Djibouti, Arabia, Somalia, Oman, Syrian Islamic Republic and vector-borne diseases for many years Sudan, Republic of Arab Republic of Iran, Kuwait, Yemen Pakistan, during the past century. Although mainly Palestine, Qatar, Tunisia, United targeted at malaria, these interventions have Arab Emirates also affected other pests and vectors. Dengue 85 000 Djibouti, Pakistan Republic of Yemen 19 countries
Japanese encephalitis 81 000 – Afghanistan, 20 countries Pakistan
Onchocerciasis 46 000 Sudan, Republic of – 20 countries Yemen
Trypanosomiasis 40 000 Sudan – 21 countries
Top 10 vector-borne diseases are responsible for 14 657 000 DALYs regionally = 11% of DALYs attributed to vector-borne diseases globally = 17% of DALYs attributed to communicable diseases regionally **Enteric infections causing diarrhoeal diseases are only partly transmitted by vectors, being more often acquired directly from faecal/oral route or via contaminated water and foodstuff *Source: World health report 2002 22 23 Management Annex 2 Terminology and An orderly and replicable approach to tackling definitions challenges and solving problems Plan Defined course of action General terms Policy Disability-adjusted life years (DALYs) A set of decision-making criteria and procedures to achieve an agreed development One DALY can be thought of as one lost year goal of “healthy” life. DALYs are calculated as the sum of the years of life lost due to Programme premature mortality (YLL) in the population, An agreed course of action within the and the years lost due to disability (YLD) for framework provided by the policies incident cases of the health condition Project Framework A self-contained building block or module Circumstances surrounding and possibly of activities, one unit of a programme affecting policies, strategies, programmes Receptive Integration Situation (e.g. country) where a particular An approach to overcome fragmentation in policies and programmes, in order to disease is not currently transmitted, but where maximize benefits from synergies and conditions are suitable for its transmission economies of scale, and exclude inefficiencies (e.g. susceptible hosts and, for vector-borne resulting from redundancies and overlap diseases, competent vectors with adequate vectorial capacity) if introduced Integrated vector management (IVM) A process of evidence-based decision-making Strategy procedures aimed to plan, deliver, monitor The optimal allocation of (limited) financial, and evaluate targeted, cost-effective and human and technical resources to support the sustainable combinations of regulatory and most efficient process of achieving the goal operational vector control measures, with a measurable impact on transmission risks, Subsidiarity adhering to the principles of subsidiarity, The concept of optimizing programme intersectorality and partnership implementation by ensuring decision-making at the lowest possible level in the political or Intersectoral administrative hierarchy Involving two or more sectors, e.g. health and agriculture; public health and military Vulnerable Situation where infection and/or vectors are Intrasectoral likely to be introduced. Involving two or more sub-sectors of the same sector, e.g. IEC and IVM; malaria and Vector leishmaniasis; diagnostic and preventive Carrier and transmitter of infection Vector competence: biological and/or mechanical ability to transmit infection
24 25 Potential vector Economic evaluation Species that is competent to transmit infection, but apparently not currently involved Cost–effectiveness analysis A comparative economic evaluation which Vector control offsets the costs of alternative actions against Interventions targeting vectors to reduce their their effectiveness using agreed effectiveness vectorial capacity indicators common to all interventions Vectorial capacity Cost–benefit analysis Mathematical expression to measure vector A comparative economic evaluation which efficiency, used to assess risk and impact of offsets the costs of alternative actions against interventions. Vectorial capacity (C) is their benefits, expressed in monetary terms expressed as: C = ma2 n p /-loge p where: Cost–utility analysis m = density of vectors in relation to man A comparative economic evaluation which a = number of blood meals taken on man offsets the costs of alternative actions against per vector per day their utility as expressed in composite p = proportion of vectors surviving per indicators that include a weighting for certain day social and demographic factors and take into n = incubation period in the vector (days) consideration certain externalities (such as – 8 days DALYs)
when they survive (1/-log ep) days. Theoretically, incidence of infection rises when C>1, incidence falls when C<1
Indicators of vector control interventions
Impact indicator A measurement of the immediate effect of an intervention in achieving its immediate objective (e.g. number of breeding places eliminated)
Outcome indicator A measurement of the effect in relation to achieving the final goal (e.g. EIP or disease morbidity)
Process indicator A measurement of the correct implementation of a sequence of essential actions
26 27