Seroprevalence of Zika virus in selected regions in Kenya

Background: The Zika virus pandemic in South America in 2015-2016 and the association of Zika virus infection with neurological complications such as microcephaly in newborns distressed the global community. There is limited data on the prevalence of Zika virus in Kenya despite evidence of its circulation in East Africa. This study aimed at assessing the seroprevalence of Zika virus in selected areas in Kenya.

Methods: Healthy adult human sera originally collected from Nairobi, Eldoret and Kisumu from 2009 to 2014 and archived at the University of Nairobi laboratories were examined for Zika virus antibodies. An IgG-based ELISA was used to screen 577 sera. Any serum tested positive by ELISA was confirmed for Zika virus infection by plaque reduction neutralization test (PRNT).

Results: The seroprevalence of Zika virus in the study population was about 0.2 % (1/577) as confirmed by PRNT. Additionally, three sera that were false positive by ELISA for Zika virus were confirmed as positive for dengue virus by PRNT.

Conclusion: There was evidence of low previous exposure to Zika virus in the study population. Of the three regions in Kenya where sera for this study were obtained, only Kisumu County had one case of previous exposure to Zika virus.