Seroepidemiology of dengue, zika, and yellow fever viruses among children in the democratic republic of the Congo

Flaviviruses suchas Zika, dengue, and yellow fever cause epidemics throughout the tropics and account for substantial global morbidity and mortality. Although malaria and other vector-borne diseases have long been appreciated in Africa, flavivirus epidemiology is incompletely understood. Despite the existence of an effective vaccine, yellow fever continues to cause outbreaks and deaths, including atleast 42 fatalities inthe Democratic Republic of the Congo (DRC) in 2016. Here, we leveraged biospecimens collected as part of the nationally representative 2013-2014 Demographic and Health Survey in the DRC to examine serological evidence of flavivirus infection or vaccination in children aged 6 monthsto 5 years. Even in this young stratum of the Congolese population, wefind evidence of infection by dengue and Zika viruses basedonresults from enzyme-linked immunosorbent assay and neutralization assay. Surprisingly, there was remarkable discordance between reported yellow fever vaccination status and results of serological assays. The estimated serop revalences of neutralizing antibodies against each virus are yellow fever, 6.0% (95%confidence interval [CI]= 4.6-7.5%); dengue, 0.4% (0.1-0.9%); and Zika, 0.1% (0.0-0.5%). These results merit targeted, prospective studies to assess effectiveness of yellow fever vaccination programs, determine flavivirus seroprevalence across a broader age range, and investigate how these emerging diseases contribute to the burden of acute febrile illness in the DRC.