The World Health Organization, WHO, confirmed that there were 32 positive cases of yellow fever infection in Nigeria between July to December 2017. The confirmed cases were part of 63 samples sent to the regional reference laboratory, Institute Pasteur de Dakar, IPD, in Senegal, for confirmation of yellow fever infection from 341 suspected cases reported from 16 states of the Federation.
The affected states according to the WHO include: Abia, Anambra, Borno, Edo, Enugu, Kano, Katsina, Kogi, Kwara, Kebbi, Lagos, Nasarawa, Niger, Oyo, Plateau, and Zamfara states. Out of the above sixteen states, WHO said Kano, Kebbi, Kogi, Kwara, Nasarawa and Zamfara states have reported confirmed cases of yellow fever.
According to the WHO: “Of 63 samples sent to IPD for laboratory confirmation of yellow fever infection, 32 were positive, 24 were negative, and 7 results pending at the time of publication of the update.
“Of the 341 suspected cases, 214 (62.8 percent) are males. The most affected age group is people aged 20 years and younger who account for 65.9 percent of cases. The total number of deaths (among suspected, probable and confirmed cases) is 45 and nine among the confirmed cases.
The WHO said although further epidemiological investigations are under way, the case fatality rate for all cases (including suspected, probable and confirmed) is 21.1 percent and 28.1 percent for confirmed cases. Further, WHO said the response to the outbreak is being coordinated by a multi-agency, multi-partner Incident Management Center and an Emergency Operations Centre (EOC) has been established to monitor the outbreak. An EOC has also been established in Kwara state and off-site support is being provided in Zamfara state.
On 14th of September 2017, the Nigeria Centre for Disease Control, NCDC, informed WHO of a confirmed case of yellow fever in Kwara State. On the 15th of September, 2017, an official notification as per the International Health Regulations (IHR) (2005) was issued by the Nigerian National IHR Focal Point.
WHO said the case-patient was a 7 year-old girl from Kwara State who developed symptoms on 16th of August 2017 including fever, vomiting and abdominal pain.
WHO says surveillance for yellow fever has been intensified nationally and a one-week training course was conducted in Lagos to improve diagnosis of yellow fever and measles, with rapid response teams (including epidemiologists and entomologists) from NCDC and WHO were deployed to support local authorities investigate this event further in Kwara, Kogi, and Plateau states, to assess the risk of further amplification, and to assist in conducting reactive vaccination campaigns, among other activities.
The Agency noted that there is currently a moderate risk of regional spread due to the proximity of affected states (Zamfara, and possibly Kebbi) and recommends vaccination against yellow fever for all international travellers nine months of age and older going to Nigeria, as there is evidence of persistent or periodic yellow fever virus transmission. Nigeria requires a yellow fever vaccination certificate for travellers over one year of age arriving from countries with risk of yellow fever transmission.
