[Epidemiology of cutaneous leishmaniasis in Bolivia. 1. Description of study zone and prevalence of the disease].

An epidemiological survey of tegumentary leishmaniasis (Leishmania (Viannia) braziliensis) was carried out in three regions of Bolivia in the Andean foothill and Amazonian forest. It was based on the record of lesions and scars on all the inhabitants of selected representative villages. In the Yungas, an area cultivated from the XVIIth century, males and females are equally infested, mostly before they were 10 years old (65%); 48% of scars were on the head. In Alto Beni and Pando, areas covered with primary rain forest, males are significantly more affected than females. The majority of scars were on the legs. The males of the three areas were equally affected. These results suggest that: --in the Yungas, contamination takes place among children in villages during the night; --in the Alto Beni and in the Pando, the infection rate is linked to the professional activities of adults, and men are more at risk than women. Only 7% of the lesions are evolving in grave forms of mucocutaneous ulcers. These forms represent the main load of the disease from the public health point of view. It has been found heavier in the Yungas (1.32%) and in the Alto Beni (1.14%) than in the Pando (0.21%). It should be noted that the first infection can give raise to several lesions. But reinfections are rare, which supports the view that the first infection is protective against the following ones.