Using NOAA-AVHRR Data to Model Human Helminth Distributions in PlanningDisease Control in Cameroon, West Africa
Human helminth infections [intestinal nematode infections such as Ascaris lumbricoides, Trichuris trichiura, and hook- worm, and schistosome infections such as Schistosoma haematobium and S. mansoni] affect more than a quarter of the world’s population, with potential consequences for the health and nutritional and educational development of infected individuals. The advent of broad-spectrum anthelminthic drugs that are cheap, safe, and simple to deliver has meant that control has become a viable option for many countries. Because helminth infections patterns are highlyheterogeneous, methods to identify priority areas for intervention against intestinal nematode and schistosome will enhance the eflcacy of control. This paper describes the use of NOAA-AVHRR data to develop logistic regression models that predict the prob- ability of infection prevalence greater than 50 percent, and thus warrant mass treatment for intestinal nematodes and schistosomes, according to WHO’S criteria. Moreover, by overlaying the resulting risk maps on population surfaces, it is possible to estimate the school-aged population size requiring mass treatment and also provide an estimate of program costs.