Spectrum of Rift Valley fever virus transmission in Kenya: insights from three distinct regions.
Rift Valley fever virus (RVFV) is an emerging pathogen that maintains high biodefense priority based on its threat to livestock, its ability to cause human hemorrhagic fever, and its potential for aerosol spread. To define the range of human transmission during inter-epidemic and epidemic periods in Kenya, we tested archived sera from defined populations (N = 1,263) for anti-RVFV IgG by ELISA and plaque reduction neutralization testing. RVFV seroprevalence was 10.8% overall and varied significantly by location, sex, and age. In NW Kenya, high seroprevalence among those born before 1980 indicates that an undetected epidemic may have occurred then. Seroconversion documented in highland areas suggests previously unsuspected inter-epidemic transmission. RVFV seroprevalence is strikingly high in certain Kenyan areas, suggesting endemic transmission patterns that may preclude accurate estimation of regional acute outbreak incidence. The extent of both epidemic and inter-epidemic RVFV transmission in Kenya is greater than previously documented.
LaBeaud
A Desiree
AD
Division of Pediatric Infectious Diseases, Case Western Reserve University, Rainbow Babies and Children's Hospital, Cleveland, Ohio 44106, USA. adl14@case.edu
Ochiai
Yoshitsugu
Y
Peters
C J
CJ
Muchiri
Eric M
EM
King
Charles H
CH
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005843:Geography; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012295:Rift Valley Fever / Q000453:epidemiology / Q000635:transmission*; D012296:Rift Valley fever virus / Q000276:immunology* / Q000472:pathogenicity; D016036:Seroepidemiologic Studies; D013997:Time Factors
D000914:Antibodies, Viral