The impact of water on health and ill-health in a sub-Saharan African wetland: Exploring both sides of the coin

Wetlands are a source of water out of which humans derive their livelihoods in Sub-Saharan Africa. They are often over-utilized and expose humans to disease-causing infectious agents. This calls for an evaluation of the role of water, sanitation and hygiene (WASH) and their effects in disease prevention and transmission in wetlands. A health risk assessment based on syndromic surveillance of self-reported abdominal complaints and fever gathered from a rural wetland in semiarid Kenya is presented with symptoms serving as proxies for real health threats in wetlands. The incidence of abdominal complaints was significantly higher for those using unimproved water sources compared to improved water users (odds ratio 7.5; 95% CI 2.59-26.9; p=0.001). Drainage of stagnant water near the house (odds ratio 0.2; 95% CI 0.08-0.54; p=0.002) and sanitary hygiene (odds ratio 0.4; 95% CI 0.71-0.97; p=0.056) were associated with reduced risk of abdominal complaints. Drainage of water was also associated with reduced risk of fever (odds ratio 0.3; 95% CI 0.02-0.59; p=0.002) and so was the use of mosquito nets (odds ratio 0.6; 95% CI 0.39-0.02; p=0.063). Usage of wetlands in the afternoon, e.g. for irrigated agriculture, increased the incidence of fever (odds ratio 1.5; 95% CI 0.91-2.33; p=0.040). Overall, there appears a greater likelihood of reducing pathogen exposure in the domestic than in the occupational domain or in the proximity to the wetland. We show that WASH, environmental hygiene and human behaviour are risk factors associated with the contraction of diseases characterized by abdominal complaints (e.g. diarrhoea) and fever (e.g. malaria) in wetlands. The same factors also have the potential to promote human health in the context of wetlands. We demonstrate the applicability of syndromic approaches in surveillance-scarce areas and emphasize the importance of adopting an integrated health-based wetland management that considers WASH and incorporates strategies based on grassroots level risk assessments.