On 16 July 2019, the Ebonyi State Ministry of Health received information about suspected yellow fever cases in Ndingele ward, Izzi Local Government Area (LGA), Nigeria. The cases had symptoms of fever and jaundice, reported with onset since May 2019. As of 30 August 2019, a total of 84 suspected yellow fever cases, including 26 deaths (case fatality ratio: 31 %), have been reported across nine LGAs within Ebonyi State. Of the suspected yellow fever cases, fifty-five per cent (46/84) are male. The most affected age group is 0-9 years (28 cases, 33%), followed by age groups 20-29 years and above 30 years each with 20 cases (24%). The 10-19 year age group has the least number of cases (16 cases, 19%). Seventy-nine per cent of suspected cases (66/84), including seven confirmed cases positive by real-time polymerase chain reaction (RT-PCR) are reported from Izzi LGA which is located in the north-eastern part of the State, bordered with Cross River State in the east, and Benue State in the north. One case has been confirmed in an international worker involved in the extractive industry in Izzi LGA, and residing in adjacent Abakiliki LGA (an urban centre in the State).
The assessment conducted by the LGA rapid response team (RRT) and national agencies found low vaccination coverage and poor routine immunization documentation. Community surveys were conducted and yellow fever vaccination coverage was estimated to be 56% (64% for children aged less than 5 years and 48% for those older than 5 years of age). Though Nigeria introduced routine vaccination for yellow fever into the immunization schedule in 2004, most adults remain susceptible and overall population immunity is low. Although no entomological studies were conducted at the time, the geography and vegetation of the affected state is compatible with the presence of the Aedes mosquitoes, as illustrated by the transmission patterns.