Yellow fever vaccination in Nigeria: focus on Oyo State

Abstract

Background: National vaccination campaigns prevented yellow fever virus epidemics in Nigeria. A build-up of Aedes aegypti mosquitoes have been found in parts of the rain forest region that was the hotbed of previous epidemics. This study provides information on the annual vaccination counts in some major vaccination centers, vaccination status of some patients visiting the hospital for malaria and typhoid tests; and the vector density.

Methods: Aedes aegypti were caught from two locations in Ibadan between May 2013 and June 2014. Structured questionnaires were administered to patients visiting Adeoyo Hospital Yemetu Ibadan with secondary data collected from three major vaccination centres.

Results: Out of 801 patients visiting Adeoyo specialist hospital Yemetu for malaria parasite examination and widal tests, 799 had no yellow fever vaccination. The childhood YFV vaccination coverage was 40%, 73 %and 63% in 2012, 2013 and 2014 respectively. Two hundred and thirty-six Aedes aegypti were caught intermittently, over a period of fourteen months.

Conclusion: A lot of people in Oyo State are unvaccinated. The steady presence of Aedes aegypti underscores the risk of yellow fever hence the need for sustained surveillance. Indiscriminate discarding of hollow containers has immensely increased breeding of the vectors and should be discouraged.

Keywords: Yellow fever, vaccination, Aedes aegypti, Nigeria