Chagas' disease epidemiology in the province of General Paz, Argentina

Abstract

OBJECTIVE: The aim of this study was to evaluate triatomine colonization in domestic and peridomestic ecotopes and to assess the seroprevalence of Chagas' disease in rural areas. METHODS: The study was carried out in the province of General Paz, Corrientes, Argentina. Human dwellings and peridomestic ecotopes were randomly selected. Triatomines were collected using the man/hour/capture method. The insects were taxonomically determined and classified by age and sex. Trypanosoma cruzi infection was detected through direct microscopy of feces and polymerase chain reaction (PCR). Diagnosis of Chagas infection in volunteer residents was performed using indirect hemagglutination (IHA) and immunoenzimatic assay (ELISA) . Infestation, density, colonization, natural infection and dispersion indexes were recorded. RESULTS; A total of 42 households and 50 peridomestic areas were examined. Triatoma infestans domestic infestation and infection indexes were 23.8 and 19.4; respectively. Density, colonization and dispersion indexes were 2.1; 47.0 and 50.0; respectively. Of all, 5.9% of peridomiciles were infested by T. infestans and 11.8% by Triatoma sordida. Trypanosoma cruzi infection was observed in 2.0% of T. sordida. The seroprevalence rate obtained from 85 human sera analyzed was 22.3%. CONCLUSIONS: The results suggest a halt in T. cruzi transmission in the study area. Nevertheless the presence of seroreactive individuals and infected T. infestans vectors might facilitate the resurgence of the transmission cycle. Control actions with the use of insecticides might be considered in order to eliminate vector populations.