The Ministry of Health Singapore has been monitoring the development of the monkeypox situation in Nigeria. As of 13 Oct 2018, Nigeria reported a total of 280 suspected and 116 confirmed cases across 26 and 17 states respectively, since the onset of the outbreak of monkeypox in Sep 2017.
Between 7 and 11 Sep 2018, the United Kingdom reported two imported monkeypox cases from Nigeria, and a third case in a health care worker infected via secondary transmission from one of the two imported cases. On 12 Oct 2018, the Israeli Ministry of Health reported an imported case of monkeypox involving an Israeli man who contracted the disease in Nigeria. The three exported cases are the result of a large sustained monkeypox outbreak in Nigeria.
The monkeypox virus is a member of the Orthopoxvirus genus that also includes the smallpox (variola), cowpox and vaccinia viruses. Although the monkeypox virus is not directly related to the variola virus, smallpox vaccination may prevent monkeypox infection.
Spread of monkeypox may occur when a person comes into close contact with an infected animal (rodents are believed to be the primary animal reservoir for transmission to humans), an infected human, or materials contaminated with the virus. The virus enters the body through broken skin (even if breaks are not visible), the respiratory tract, or the mucous membranes (eyes, nose, or mouth). The incubation period in humans ranges between 5 to 21 days (typically 6 to 16 days).
The majority (>70%) of infected persons are symptomatic, and early symptoms of monkeypox include fever, headache, muscle ache, backache, lymphadenopathy, and a general feeling of exhaustion (asthenia). Within 1-3 days after the onset of fever, infected persons will develop a maculopapular rash, often starting from the face before becoming generalised (centrifugal distribution), including involvement of palms and soles in up to 75% of cases. The lesions progress to become vesicles and then pustules, before crusting occurs in approximately 10 days, which then spontaneously fall off. The disease is typically self-limiting, with symptoms usually resolving spontaneously within 14-21 days. However, the infection can be fatal, particularly in young children, with a reported mortality rate of 1% to 10% during outbreaks.
Persons presenting with a history of fever and a vesicular rash should be asked about travel from Nigeria within 3 weeks from the onset of illness. The diagnosis can be confirmed by the National Public Health Laboratory (NPHL) using a variety of PCR tests. Clinicians should contact the NPHL via their hospital's diagnostic laboratories, and send swabs from vesicles (blood is a less preferred alternative due to lower sensitivity) in a dry and sterile tube (without universal transport medium) for further diagnostic testing.
Suspect and confirmed monkeypox cases should be isolated, preferably in a negative pressure isolation (NEP) room. Healthcare workers caring for these cases should practice strict hand hygiene and don personal protective equipment including disposable gowns, gloves, N95 masks or equivalent, as well as eye protection. There is no specific antiviral treatment, and clinical management is supportive. Suspect or confirmed cases can also be transferred to the National Centre for Infectious Diseases for isolation and management, after informing MOH (below).
As monkeypox is an Emerging Infectious Disease, all suspected cases of monkeypox should be reported to MOH immediately. Please call the Surveillance Duty Officer of the Communicable Diseases Division, followed by submission of the MD131 Notification of Infectious Diseases Form through the Communicable Diseases Live & Enhanced Surveillance (CDLENS) system or by fax to 6221-5528/38.
