| This dissertation explores the relationships between land cover and malaria vector larval presence, human biting rates, and human malaria prevalence.; Methods. Larval Anophelines were collected from bodies of water along 125km of transects once every three weeks between September 2000 and September 2001 (total of 1224 bodies of water, sampled 4.5 times each).; Results. In the larval study, 7.4% of the bodies of water were positive for A. darlingi at least once (n = 90). Seventeen species of Anopheles larvae were collected. The presence of A. darlingi larvae was positively correlated with algae, leaf litter, emergent grasses, the aguaje palm (Mauritia flexuosa), clear water, ponds between 51 and 100m in circumference, fish farms, the distance to varillal forest (forest growing on sandy soils), the amount of tall secondary growth, and the amount of impervious surface. It was negatively correlated with current and distance to deep water. In the adult study, 12 species of Anopheles were collected. The mean human biting rate for A. darlingi was 3.0/6-hr collection night. This biting rate was positively associated with the ambient temperature, the amounts of deep water, tall secondary growth, deforested land, impervious surface, and the months of May through August 2001. It was negatively associated with the amount of forest, the distance to deforested land, a new moon, and the months of February through April, 2001. The human malaria study revealed that 1.5% were infected with Plasmodium falciparum, and 2.3% were infected with P. vivax. The falciparum malaria infection rate was positively associated with fever, the time of departure to the farm, the presence of a fish farm, the number of years living in the same house, the amount of deep water, the amount of tall secondary growth, and the amount of shrub. It was negatively associated with the amount of deforested land, an elevated house (on stilts). Vivax malaria infection was positively correlated with fever, hunting at night, and the interaction term being ten years or older and exiting the bed net after 6am. It was negatively correlated with the amount of forest and the distance to tall secondary growth. Conclusion . Environments altered by humans in this study region were consistently positively correlated with vector breeding sites, biting rates, and human malaria infection. Even after adjusting for climate and household variables, the amount of tall secondary growth, shrub, and impervious surface were predictive of these three outcome measures. (Abstract shortened by UMI.)... |
