Abstract:
West Nile Virus (WNV) is considered to be one of the most wide spread group of
arboviruses in Africa, Asia and America. The geographical range of the WNV has
broadly extended over the years and the virus has transcended geographical barriers and
become established even in non-endemic areas. This sero-survey study reports WNV
activity in Trans Nzoia district, Kenya. The study cohort consisted of 1114 serum
samples from febrile patients attending three different health facilities in the area.
Antibodies to West Nile Virus (WNV) were detected in 105 (9.8%) of the patients by
indirect IgG Enzyme Linked Immunosorbent Assay (ELISA). Of these, 12 (1.1%)
infections were confirmed by Plaque Reduction Neutralization Test (PRNT) therefore
the seroprevalence of WNV in the area. This suggests that there is low WNV activity in
Trans Nzoia district, Kenya. The detection of low levels of WNV and the low intensity
of the severity of the clinical symptoms suggest a less virulent strain is in circulation or
previous exposure to other closely related flavivirus. The linear increase in WNV IgG
and IgM seroprevalence rates with age suggests continuous exposure of this population
to the virus. Patients of both genders were exposed with 69% female and 31% male
positive for WNV, this disparity can be attributed to cultural practices and activities that
increase the risk of exposure among the female subjects. This study provides baseline
information for further research and strategic planning. Therefore despite the low levels
of WNV, appropriate interventions should be established by the public health authorities
in view of the fact that it is a public health threat.
