Orthobunyavirus antibodies among humans in selected parts of the Rift Valley and northeastern Kenya

Abstract

Ngari, Bunyamwera, Ilesha, and Germiston viruses are among the mosquito-borne human pathogens in the Orthobunyavirus genus, family Bunyaviridae, associated with febrile illness. Although the four orthobunyaviruses have been isolated from mosquito and/or tick vectors sampled from different geographic regions in Kenya, little is known of human exposure in such areas. We conducted a serologic investigation to determine whether orthobunyaviruses commonly infect humans in Kenya. Orthobunyavirus-specific antibodies were detected by plaque reduction neutralization tests in 89 (25.8%) of 345 persons tested. Multivariable analysis revealed age and residence in northeastern Kenya as risk factors. Implementation of acute febrile illness surveillance in northeastern Kenya will help to detect such infections.