Ecoepidemiological evaluation of visceral Leishmaniasis in the Zenu Indigenous community of San Andres de Sotavento, Cordoba: first step for its control

Abstract

During three years (1990-1993), the applica­tion of the ecoepidemiological method in the endemic focus of visceral leishmaniasis in the Caribbean coast region of Colombia allowed for the understanding of the mechanism of dis­ease transmission. A new vector for American visceral leishmaniasis was demonstrated: Lutzomyia evansi. It is the main vector in this region. Leishmania infantum (=L. chagasi) is responsible for visceral leishmaniasis as well as cutaneous leishmaniasis. L braziliensis was also found to produce cutaneous lessions. The opossum (Didelphis marsupialis) is an im­portant reservoir for L. infantum (23% infec­tion) and for Tripanosoma cruzi (18% infec­tion). In addition, 25% of dogs showed IFAT (+) for Leishmania. The application of Thorn­thwaite's humidity coefficient allowed for the localization of the distribution area for La. evansi and the determination of the limits of the transmission focus (the macro focus). The population dynamics of the vector showed that the rain season (October - December) is the period of higher transmission and that children under three years old are the human population at higher risk. Currently, the first program for the control of visceral leishmaniasis in Colom­bia is being designed and performed with the aid of these elements.