Human Trypanosomiasis in the Eastern Plains of Colombia: New Transmission Scenario.

Characteristics of Trypanosoma cruzi infection were studied in a rural area of the eastern plains of Colombia. Using enzyme-linked immunosorbent assay and indirect fluorescent-antibody tests, the infection was determined in 11.6% of the inhabitants of 142 dwellings. During 6 months of community surveillance, in 42.3% dwellings, 609 triatomines were collected (597 Rhodnius prolixus and seven, three, one, and one of Panstrongylus geniculatus, Psammolestes arturi, Eratyrus mucronatus, and Triatoma maculata, respectively). Rhodnius prolixus was found in 80% peridomiciliary Attalea butyracea palms examined with baited traps, and its infection with T. cruzi was 30% and 38.5% in dwellings and palms, respectively. Trypanosoma cruzi was isolated in five of 35 triatomines and in one of 24 dogs. The blood of domestic and wild animals was identified in triatomines collected in the intradomicile and in palms. These results support the extension of the wild cycle of T. cruzi to human dwellings and the characterization of a new scenario for transmission in Colombia.

ITS-RFLP- and RAPD-based genetic variability of Trypanosoma cruzi I, human and vector strains in Santander, Colombia.

Chagas disease is a severe public health problem in Latin-American countries. In Colombia, the predominance of Trypanosoma cruzi I has been described in the literature, with a broad heterogeneity between strains. However, most of the studies carried out centered on isoenzyme analysis, with a smaller number that focus on other molecular methods. In this report, we discuss the results of a molecular analysis of T. cruzi I strains, isolated from the domestic cycle, from the department of Santander, one of the territorial divisions where the prevalence of infection is highest. Internal transcribed spacer-restriction fragment length polymorphism and random amplification of polymorphic DNA were used to characterize 16 strains from human and vector (Triatominae) hosts. The data reveal a clustering based on the biological origin. Human and vector strains grouped separately; however, three vector strains clustered together with human strains. These results indicate that genetic differences exist in the strains that infect both hosts. We conclude that T. cruzi I populations in the domestic cycle of transmission of Chagas disease in Santander are heterogeneous and are composed of different clones. The epidemiological and biological implications are discussed.