Yellow fever (YF) remains a public health problem in Cameroon: descriptive analysis of the national database (2010-2016, 50th epidemiological week)

Abstract

Introduction : there is resurgence of Yellow fever (YF) cases in Africa. In Cameroon, confirmed cases of YF continue being registered (20 cases in 2015), despite several control measures put in place, including, several vaccination campaigns (target > 9 months) conducted nationwide, the last one dating May 2015. We aimed to describe the epidemiological profile of YF cases in Cameroon for the improvement of surveillance and controls strategies. Methods : we analyzed the Expanded Program of Immunization’s YF case database, from 2010 to 2016 with Epi Info 7. Sample transport duration, vaccination status of suspected cases, socio demographics, trends and geographic distribution of confirmed cases were analyzed. A confirmed case, was every positive case at seroneutralisation, with no previous YF vaccination. Differences between the frequencies of cases was determined using Chi-square (X 2 ). Results : a total of 13,837 suspected cases of YF were reported, and 13,807(99.7%) tested. The proportion of samples sent on time to the laboratory decreased from 25% in 2010 to 18% in 2016. In 2016, 56% of suspected cases were unvaccinated or had unknown immunization status. A total of 109 suspected cases were confirmed, giving a predictive positive value of 0.8%. The annual incidence of cases varies, with two peaks in 2011 (1.3/1.000.000hbts) and 2015 (1.1/1.000.000hbts), and a mean of 7 cases/1.000.000hbts/year. Cases were recorded in 58/189 health districts, mostly in rural zones 72 (66%) p Conclusion : these findings highlight that YF remains a public health problem in Cameroon, with probable seasonal trends and low immunisation status of the population. Emphasis should be placed on conducting periodic and high quality vaccination campaigns in order to reduce the risk and prevent outbreaks.