[Tegumental leishmaniasis in Las Lomitas, Province of Formosa, Argentina, 1992-2001].

Las Lomitas Hospital reported 85 cases of tegumentary leishmaniasis between 1992 and 2001. The cases were males (72.9%), 91.8% older than 10 years, 10.5% presented mucosae involvement. A single ulcer on lower limbs was the most frequent manifestation. The epidemiological and clinical patterns were consistent with the infection due to Leishmania (Viannia) braziliensis. The annual distribution of ulcers onset was bimodal, the frequency of cases had a significant association with the Bermejo river volume, and the rainfall of the previous year. Intradermoreaction and recalling questions suggested that fishing in the river was the main risk activity. Among 1018 Phlebotominae collected, 97.1% were Lutzomyia neivai, 2.3% L. migonei and 0.6% L. cortelezzii (0.6%), the peridomestic/gallery forest of the Bermejo river proportion was 1/9, with similar composition to the populations around the same river in Salta province. The increase of cases since 1992, the ongoing environmental changes due to developmental works, and the potential installation of a periurban transmission cycle, require an active surveillance of cases and entomological components in the Chaco region.