Serological Evidence of Exposure to Onyong-Nyong and Chikungunya Viruses in Febrile Patients of Rural Taita-Taveta County and Urban Kibera Informal Settlement in Nairobi, Kenya
Moses Muia Masika,
Essi M. Korhonen,
Teemu Smura,
Ruut Uusitalo,
Joseph Ogola,
Dufton Mwaengo,
Anne J. Jääskeläinen,
Hussein Alburkat,
Yong-Dae Gwon,
Magnus Evander,
Omu Anzala,
Olli Vapalahti,
Eili Huhtamo
Affiliations
Moses Muia Masika
KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya
Essi M. Korhonen
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Teemu Smura
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Ruut Uusitalo
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Joseph Ogola
KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya
Dufton Mwaengo
Department of Medical Microbiology, University of Nairobi, POB 19676, Nairobi 00202, Kenya
Anne J. Jääskeläinen
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Hussein Alburkat
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Yong-Dae Gwon
Department of Clinical Microbiology, Umeå University, 90185 SE Umeå, Sweden
Magnus Evander
Department of Clinical Microbiology, Umeå University, 90185 SE Umeå, Sweden
Omu Anzala
KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya
Olli Vapalahti
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Eili Huhtamo
Department of Virology, University of Helsinki, 00014 Helsinki, Finland
Several alphaviruses, such as chikungunya (CHIKV) and Onyong-nyong (ONNV), are endemic in Kenya and often cause outbreaks in different parts of the country. We assessed the seroprevalence of alphaviruses in patients with acute febrile illness in two geographically distant areas in Kenya with no previous record of alphavirus outbreaks. Blood samples were collected from febrile patients in health facilities located in the rural Taita-Taveta County in 2016 and urban Kibera informal settlement in Nairobi in 2017 and tested for CHIKV IgG and IgM antibodies using an in-house immunofluorescence assay (IFA) and a commercial ELISA test, respectively. A subset of CHIKV IgG or IgM antibody-positive samples were further analyzed using plaque reduction neutralization tests (PRNT) for CHIKV, ONNV, and Sindbis virus. Out of 537 patients, 4 (0.7%) and 28 (5.2%) had alphavirus IgM and IgG antibodies, respectively, confirmed on PRNT. We show evidence of previous and current exposure to alphaviruses based on serological testing in areas with no recorded history of outbreaks.
