A case-control study of environmental and behavioural risk factors associated with multiple parasitic infections in Western Kenya
Many rural African villages are characterized by high prevalence of endemic parasitic diseases with cases of multiple parasite infections often too being common. This study was conducted in the Western Province of Kenya within a 45 km radius from Busia town, falling within the Lake Victoria Crescent Zone. The study aimed at determining whether there was a relationship between contact with particular environmental features, or specific human social behaviour and the risk of infection with multiple parasitic diseases. The sample frame for this nested case-control study comprised the 467 individuals randomly selected and sampled from this study site as part of a larger, on-going, cross-sectional study. The participants had been screened for a variety of zoonotic and non-zoonotic diseases and questionnaires administered to obtain information on specific aspects of their social behaviour. From the sample frame, 24 subjects with multiple parasitic infections defined as cases, were randomly selected and matched for age and sex with 24 other individuals who had one or no infection, herein defined as controls. Cases and controls were followed to their daily activity points using a GPS waypoint data of the activity points mapped. The study revealed high prevalence of parasitic infections. The infections co-occurred spatially within the same geographic setting with cases of sampled individuals bearing multiple infections at anyone time being common. Cases and controls displayed a relatively homogeneous social behaviour and visited nearly the same activity points. Conditional logistic regression analysis did not reveal any significant difference between cases and controls with respect to any difference in their social behaviour and . interaction with potentially risky environments and thus perceived odds of acquiring parasitic infections. These findings are an initial step to further research into the dynamics of human-environment-parasite interaction in an environment where parasitic infections are co-endemic. The findings will also be vital in helping design long-term strategies for control.