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

Abstract

Abstract. 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.Trypanosoma cruzi infection continues to affect nearly 6 million people in 21 countries of the Americas 1 despite the success of control programs against domestic triatomines. 2There are zones where dwellings are infested by other species of Triatominae with peridomiciliary and wild ecotopes. In the Amazon, some of the more than 27 wild species described, principally of the genus Rhodnius, have made incursions into dwellings, with the risk of infecting human populations. 3In Colombia, the Andean region in the eastern zone below 2,000 m above sea level has been considered endemic for Chagas disease because of the high degree of domiciliary infestation, wide dispersion, and the high densities of Rhodnius prolixus.4,5 A decade after the adoption of a government program to control domiciliary triatomines, in our observation, this species has been controlled. However, another transmission scenario has begun to be known with checking of the wild cycle in peridomiciliary palms as a transmission risk factor in the departments of the eastern plains 6 and the reporting of high prevalence rates of human infection with T. cruzi.7 This study was conducted for the purpose of clarifying the epidemiological characteristics of this scenario in this region.In December 2008, the prevalence of T. cruzi infection was evaluated in the inhabitants of 142 dwellings in the department of Casanare, dispersed in rural areas of the municipalities of Maní (04°49′02″N/72°17′19″W) and Aguazul (05°10′23″N/ 72°33′17″W), which were fumigated by the program of VectorTransmitted Diseases (Enfermedades Transmitidas por Vectores [ETV], in Spanish) in that department. This territory corresponds to the alluvial and eolic plains of the Orinoquía, composed of flooded savannas with herbaceous and graminaceous vegetation in the humid warm thermal floor, with an average temperature of 25-27°C and an annual rainfall of 2,400-2,600 mm (Figure 1).The dwellings are constructed with brick walls, cement, ti...

Generalist host species drive Trypanosoma cruzi vector infection in oil palm plantations in the Orinoco region, Colombia

“…Previous reports in Colombia have detected vertebrate species in triatomine blood meals using ELISA and the cytochrome b gene PCR-HRM (polymerase chain reaction - high resolution melting); however, these studies identified fewer species than our study and higher taxonomic levels of sylvatic animals were not specified (bats and mice) [70, 88, 89]. For the ELISA approach, the fact that some species-specific anti-sera might not be available, could lead to unidentified species [88].…”

“…Palm trees are the natural ecotope of most Rhodnius species [39] because they provide refuge and plenty of food sources, as many vertebrate species forage there [64–66]. Attalea butyracea is a complex-crown palm tree that is ubiquitous in the Orinoco region, where large R. prolixus densities with high T. cruzi natural infection rates [67–69] and blood meals from all terrestrial vertebrate taxa, except amphibians, have been reported [70]. In this study, we present a detailed description and analysis of R. prolixus blood meals in A. butyracea palms and oil palms ( E. guineensis ) in the department of Casanare, Colombia.…”

Heterogeneity of Trypanosoma cruzi infection rates in vectors and animal reservoirs in Colombia: a systematic review and meta-analysis

“…Another interesting contrast occurs with regards to the family Felidae. Species of this family have been reported infected in studies from Argentina and Brazil [44, 45], whereas in our systematic review in Colombia only one study for this family was identified, which reported no T. cruzi infection [46].…”

Rhodnius prolixus Colonization and Trypanosoma cruzi Transmission in Oil Palm (Elaeis guineensis) Plantations in the Orinoco Basin, Colombia

“…44 Previous studies in Colombia have shown a T. cruzi infection prevalence in dogs between 50% and 70.1% in the Caribbean region, 45,46 31% in the department of Boyacá, 47 and 8.3% in the department of Casanare. 48 The role of domestic pigs in the T. cruzi transmission cycle in Colombia remains poorly studied, as only one study has reported T. cruzi infection in one sampled individual. 45 Nonetheless, in other endemic regions, such as the Brazilian Amazon Basin, pig pens adjoining human dwellings were infested with Panstrongylus geniculatus, and sampled domestic pigs were infected.…”

“…For instance, Rendon et al 7 reported a robust sylvatic cycle in a rural area located in the municipality of Mani (Casanare), with the absence of triatomines in houses and T. cruzi infection in sylvatic mammals. However, Angulo-Silva et al 48 suggested that the T. cruzi sylvatic cycle was extended to human dwellings in the same municipality. Other studies in the northeast of Colombia have indicated that sylvatic and domestic cycles do not overlap.…”