After 4 Decades, A Rare Disease Has Re-Emerged in Nigeria

A large outbreak caused by the West African clade of the monkeypox virus has hit humans living in Nigeria.

The Centers for Disease Control and Prevention (CDC) has released a research letter providing additional information into a large outbreak of a rare disease that had recently re-emerged in Nigeria in 2017: monkeypox.

The rare zoonotic infection caused by an orthopoxvirus was first identified in humans in the Democratic Republic of Congo back in 1970; it is now considered to be endemic in the country. Most outbreaks of the infection are caused by the Central and West African clades of the virus and have sprung up in the rural rainforest areas of the Congo basin and West Africa.

The last time that a case had been reported in Nigeria was in 1978, when a 4-year-old child living in the southeastern part of the country fell ill with the disease, according to the CDC. Thirty-nine years later, on September 22, 2017, a suspected case was reported to the Nigeria Centre for Disease Control (NCDC).

After the individual had been admitted to the Niger Delta University Teaching Hospital in Bayelsa State, swift action was taken. The individual was isolated, and laboratory and contact tracing was conducted by officials. The individual was 11 years of age and presented with fever, generalized rash, headache, malaise, and sore through for 11 days.

“Physical examination revealed generalized well-circumscribed papulopustular rashes on the trunk, face, palms, and soles of the feet and subsequent umbilication, ulcerations, crusting, and scab formation,” authors of the research letter write. “The patient had associated oral and nasal mucosal lesions and ulcers and accompanying generalized lymphadenopathy.”

Similar symptoms were noted in 5 other family members who were living in the household with the index patient. Upon further investigation, officials found that the index patient along with 2 of his siblings had, in fact, been in contact with a monkey belonging to a neighbor just 1 month prior to illness. However, the monkey did not have a known history of illness, and thus, it has not been identified as the source of their infections.

After suspecting monkeypox, NCDC officials took several steps to quell the potential outbreak. They included:

  • Sending epidemiologists to the area to support investigations
  • Notifying health authorities spanning all states to strengthen surveillance based on a standardized case definition
  • Activating a national Emergency Operations Centre to coordinate outbreak response (October 9, 2017)
  • Assembling all relevant stakeholders for response efforts
  • Developing interim guidelines and protocols and sending them out to all the states
  • Implementing rigorous surveillance, public sensitization, community mobilization, and case management across all states

It wasn’t until October 13, 2017, that the human monkeypox outbreak in Nigeria had been confirmed to the NCDC. By November 17, 2017, officials suspected a total of 146 cases from 22 states in Nigeria. Officials tested 107 samples out of the 134 that they had collected and 42 from 14 states were confirmed as the West African clade of the virus.

The majority (62%) of the cases were in adults between 21 and 40 years, and the majority of those infected were male; one individual died.

Officials are still working to identify both the zoonotic source of the outbreak as well as the route of transmission, although they did detect 3 family clusters, “which might suggest some level of human-to-human transmission in this outbreak,” the authors write.

The NCDC is still in the process of investigating the outbreak and channeling efforts into outbreak response.

“Further findings from our epidemiologic investigations and laboratory diagnostics, including genome sequencing, will add to the existing knowledge of West African monkeypox and help unravel uncertainties in the outbreak,” the authors conclude.

Feature Picture Source: World Health Organization / Brian W.J. Mahy, BSc, MA, PhD, ScD, DSc / CDC PHIL Library. Feature Picture Caption: This 1997 image was created during an investigation into an outbreak of monkeypox, which took place in the Democratic Republic of the Congo (DRC), formerly Zaire. Pictured here, in this photograph from the World Health Organization (WHO), was the face of a young boy, who had sustained the ravages of the characteristic maculopapular monkeypox cutaneous rash, which resembled the rash caused by the smallpox virus.