Monkeypox Nov 2017 2017 Watching brief Date of report 30 November 2017 Monkeypox Disease Not yet confirmed. The first human case in Nigeria was reported to Origin have killed and eaten a monkey with members of his household and neighbours who later showed symptoms of the monkeypox virus(1). Not yet confirmed. Probable source of disease from squirrels, Gambian Suspected Source giant rats, other rodents and primates. On 22 September 2017, three cases of suspected monkeypox was reported in Niger Delta University Teaching Hospital in Bayelsa state, Nigeria(1). Samples were sent to the WHO regional laboratory in Dakar Date of outbreak Senegal for confirmation. The outbreak was confirmed by WHO on 16 beginning October 2017 as all three samples were positive for monkeypox(1). Epidemiological linkage confirmed among the first three cases in Bayelsa state(1, 2). Date outbreak Ongoing declared over Nigeria. Affected countries Confirmed cases in Akwa Ibom, Bayelsa, Cross River, Imo, Abia, & regions Nasarawa, Benue, Delta, Edo, Ekiti, Enugu, Lagos, Rivers and Federal Capital Territory (FCT) and suspected cases in 21 states(2, 3). 1 Monkeypox – November – 2017 Clustering of cases in some states of Nigeria has been observed but no evidence of epidemiological linkage across states(2). As of 9 October 2017, 33 suspcted cases in 7 states with no deaths reported (4). As of 16 October 2017, 3 laboratory confirmed cases and 74 suspected cases from 10 states(5). As of 2 November 2017, 38 confirmed cases and 116 suspected cases Number of cases from 20 states(3). As of 19 November 2017, 42 confirmed cases and 146 suspected cases from 21 states(6). As of 30 November 2017, 59 confirmed cases in 14 states and 167 suspected cases from 21 states (2, 7) Clinical symptoms similar to smallpox but less severe. In this outbreak, most of the suspected cases have been reported to have rashes(1). Monkeypox is a self-limiting disease with symptoms lasting from two to three weeks. Severity is associated with infectious dose exposure, patient health status and is worse among children. The incubation period is usually 6 to 16 days. The infectious period can be divided into two periods(1, 8, 9): Clinical features 1. The invasion period: fever, headache, swelling of lymph node (distinctive feature), back pain, myalgia, fatigue 2. The skin eruption period (within 1-3 days after appearance of fever): various stages of rash, spreading from face to palms and soles of the feet are the most affected areas. The rash continues to evolve from maculopapules to vesicles to pustules, and eventually crusts occur in 10 days. It may take three weeks before resolution of crusts. Zoonotic transmission: Exposure to animals such as close contact with infected rodents or primates through bites,scratches or consumption of infected and inadequately cooked animal products. Infection by inoculation though contact with cutaneous or mucosal lesion on animal, especially when breaks in skin barrier. Person to person transmission: Transmission occurs through direct contact with the blood, bodily fluids, fluids from cutaneous or mucosal Mode of lesions of infected persons or via the respiratory route through transmission infected respiratory tract secretions. Congenital monkeypox can occur as the virus is transmitted across the placenta. Observational studies in the mid 1980s showed an infectious period during the first week of the rash similar to smallpox(10). A study conducted in the US 2003 examining health care worker exposure to patients with confirmed monkeypox showed that human to human transmission in an outbreak seting is rare(11). Monkeypox – November – 2017 The index case was an 11 year old male patient from Agbura, a rural settlement near Yenagoa and later presented to the Niger Delta University Teaching Hospital in Bayelsa state(1). A medical doctor and a 17 year old boy were one of the first suspected cases in Bayelsa Demographics of state(1). Male to female ratio of suspected cases was initially 3:1 and cases reduced to twice as many males as females(2, 4). The most affected group has been those aged 21-30 years old and subsequently widened to 21-40 years old (median age=30) in the most recent situation report(2, 3). No other details are available. From previous outbreaks, the CFR has been between 1-10%, mostly among young children(12). One deaths have been reported among confirmed or suspected cases in the current outbreak in a confirmed case that had background immunosuppression(2). Media reports mentioned one case alleged to Case fatality rate have committed suicide due to the of stress of illness and lack of proper counselling previously, and our sources confirm that this was a separate incident in a patient who was admitted to the same hospital as the initial cases were being treated and unrelated to the outbreak(13). Permanent scarring, disfigurement and death. Prognosis may be worse Complications for patients who are younger, have other co-morbidities such as malnutrition or those who are immunocompromised. There is no vaccine for monkeypox. Vaccination against smallpox confers cross protection for monkeypox and has been shown to be 85% effective against monkeypox(14). However, the vaccine is currently not publicly administered in Nigeria. Patients and response activities are being managed by public health Available authorities and Nigeria Centre for Disease control especially in states prevention with confirmed cases. Recommendations for infection prevention and control measures: • Contact precautions in healthcare setting • Appropriate use of personal protective equipment • Proper hand hygiene • Safe handling of meat products • Avoid close contact with possible source of infections Available Treatment is supportive and based on the patient’s clinical condition. treatment Symptomatic relief is also provided. Two previous outbreaks were reported in Nigeria in 1971 and 1978 Comparison with with 2 cases and 1 case respectively amongst individuals who were not past outbreaks vaccinated against smallpox. Cases were linked to consumption of Monkeypox – November – 2017 meat obtained from tropical rainforests (15). The outbreak in 1971 involved a 4 year old female index case. The secondary case was her 24 year old mother. The ingle case identified in 1978 was a 35 year old man(15). Since then monkeypox has remained a disease of Central and West African countries except in 2003 when 37 confirmed and 10 probable cases were reported across six states in the US, the first reported outbreak outside of Africa where those affected had close contact with pet prairie dogs (rodent of Cynomys species) imported from the endemic region(16). The largest outbreak ever reported in Africa was in 1996 in the Democratic Republic of Congo with more than 70 cases that lasted for one year(17). This was associated with close contact with squirrels and person to person transmission. The current outbreak has significantly more cases than previous outbreaks when probable and confirmed cases are included(17). • Uncertain source of infection • Rapid spread of infection across multiple states within few weeks, linkage between cases yet to be confirmed, still a possibility of separate clusters outbreaks • Unusual features Mode of transmission unclear, for example, how much is due to human to human transmission • Delayed diagnosis of infections as unable to diagnose the disease with laboratory confirmation in Nigeria • Large susceptible population with no prior immunity to monkeypox following cessation of smallpox vaccine in 1980 Uncertain source of epidemic Monkeypox is a zoonotic disease. The causative agent: monkeypox virus is in the genus orthopoxvirus which is endemic to Central and Western African countries of which Nigeria is a part of. Previous studies have identified two geographically disjunct clades of the virus: Congo Basin and West Africa clades(18). Isolates from Nigeria have been obtained on opposite sides of the Niger river and are more genetically divergent than other samples isolated from the West African Clade indicating that rivers could play a role in the differentiation of monkeypox virus (19). All cases in West Africa have occurred in tropical rainforest areas and Critical analysis clustering of cases has been observed within families(15, 20). People living close to forested areas have higher risk of exposure and could have subclinical infections that have gone undetected due to lack of diagnostic capabilities, low risk perception due to rarity of disease and closeness of symptoms with chickenpox(17). The clinical course of the disease among people infected with Western African strain was observed to be milder with reduced human to human transmission compared to the other strain(18). Although the current outbreak strain is yet to be confirmed it is likely to be closely related to the Western African strain. Preliminary genetic sequencing suggests multiple sources Monkeypox – November – 2017 of introduction of the virus into the population across various states according to the NCDC latest situation report(2). The precise mode of human infection is not known and no animal reservoir has been confirmed. Close association of cases with wild animals such as monkeys, rodents and squirrels leading to bites or through consumption of bush meat is a risk factor for human infection(21). There is a high probability the current outbreak originated from monkeys, with the index case reported to have killed and consumed a monkey prior to exhibiting symptoms(1). In a qualitative study of Nigerian hunters, participants reported having contact with primates more than with any other wildlife either as pets or through hunting for trade, and 87% reported consuming primates. Monkeys were listed among the most desirable animals to consume and also used for medicinal purposes(22). The role of human to human transmission is unclear in this outbreak. The possibility of the virus being used as a bioterrorism agent cannot be ruled out as well(9). Implications of eradication of smallpox An unexpected consequence of smallpox eradication is an observed rise in monkeypox cases in the decades since smallpox eradication.