Human-ecological determinants of Anopheles larval site occurrence, mosquito control activities, and reported malaria in an urban area of coastal Kenya

The occurrence of potential larval habitat, the use of mosquito control, and reported malaria were studied in relation to community and household level ecological variables. Malindi, Kenya was mapped using global positioning systems (GPS), and a geographic information system (GIS) was used to overlay a measured grid, which served as a sampling frame for this research. Grid cells were stratified and randomly selected according to levels of drainage. A stratified cross-sectional survey was conducted in November and December 2002 to collect entomological and human ecological data at the community, household, and aquatic habitat level. A hierarchical multiple logistic regression model was used to test relationships between the presence of potential anopheline larval habitat and urban agriculture at the community level. Multiple logistic regression was used to test relationships between human activities and the use of mosquito control and reported malaria at the household level. This study demonstrated that urban agriculture was not associated with the development of larval habitat after controlling for potential confounders associated with distance, drainage, access to resources, and the overall abundance of human activity. As well, this study found that few of the human-ecological variables measured were significantly associated with the use of mosquito control or reported malaria at the household level. The geographic sampling strategy employed was effective for linking human survey data with field based entomological data at the community level, but was limited in terms of it's ability to adequately sample human populations at the household level. In the absence of sustainable community level mosquito control mechanisms, many urban residents may be at increased risk of encountering infectious mosquitoes in urban environments.