Five years' observations of rural malaria in Eastern Colombia.

Abstract

Summary Malaria is endemic in all the region between the slopes of the eastern range of the Andes and the borders with Venezuela and Brazil. The malaria indexes vary according to the distribution of the anopheline species; of the 28 anophelines found in the area, A. darlingi has proved to be, as in other parts of South America, the most effective vector; its distribution, however, is restricted to certain areas. Most of the savanna country of Eastern Colombia is free from darlingi and, though the savanna anophelines such as A. pessoai, A. peryassui and A. parvus are extremely abundant throughout the nine months of the rainy season, there are always low malaria indexes. The fertility of the soil in the areas covered by darlingi has attracted in recent years a considerable number of agricultural laborers from other parts of the country, but the poor soil of the savannas is hardly fit for agriculture and there a more stable population has been devoted mainly to cattle breeding. Malaria has a rural character throughout Eastern Colombia. The house-haunting anophelines, including darlingi, seldom venture into the urban areas; they are not found resting in houses during the daytime, thus greatly reducing the effect of DDT. A. darlingi, though more closely associated with man than the other anophelines, is nevertheless found also in uninhabited areas and feeds normally on wild animals.