RESUMEN
Chagas disease is an enzootic disease, in which the flagellate Trypanosoma cruzi infects a large variety of animals. Humans are accidentally infected due to the migration into wild environments. To identify T. cruzi discrete typing units (DTUs), 19 Brazilian isolates from different biomes and hosts were analyzed by PCR amplification of 24Sα rRNA, 18S rRNA and mini-exon gene sequences. The majority of the isolates was classified as TcIIb (TcII) but subtypes TcIIc (TcIII) and TcIId (TcV) were also identified. In addition, in monkeys TcI was detected.
Asunto(s)
Enfermedad de Chagas/parasitología , Trypanosoma cruzi/clasificación , Animales , Brasil , Didelphis/parasitología , Exones/genética , Genotipo , Humanos , Leontopithecus/parasitología , Reacción en Cadena de la Polimerasa , Enfermedades de los Primates/parasitología , Primates , ARN Ribosómico/genética , Enfermedades de los Roedores/parasitología , Roedores , Triatominae/parasitología , Trypanosoma cruzi/genéticaRESUMEN
Maps are a useful tool that permits correlation of landscapes with hotspots of parasite transmission. Here, they were used as a tool for geovisualization to evaluate variables involved in the transmission of Trypanosoma cruzi among small wild mammals in an area endemic for Chagas disease, the "Serra da Capivara" National Park (PARNA) and its surroundings in Piauí State, Northeast Brazil. The implementation of a Geographical Information System (GIS) allowed the observation that a previously noted aggregated distribution of Triatoma sordida and Triatoma brasiliensis, T. cruzi prevalence and infection pattern of small wild mammals was directly or indirectly influenced by the local relief and human action. Small mammalian species diversity was higher in mesic refugia inside the park and in its buffer zone and lower in the disturbed area by anthropic activities. Didelphis albiventris was more abundant in the areas affected by human action. Thrichomys laurentius demonstrated to be an eclectic species and a competent reservoir of T. cruzi, being infected in all study areas. Small wild mammals infected with the TCII genotype of T. cruzi were localized only in the buffer zone of PARNA while TCI infected specimens were found in both areas, inside the PARNA and its buffer zone. The impact of biodiversity loss on the transmission cycle of T. cruzi in the wild environment was discussed.
Asunto(s)
Animales Salvajes/parasitología , Enfermedad de Chagas/veterinaria , Conservación de los Recursos Naturales , Sistemas de Información Geográfica , Mamíferos/parasitología , Trypanosoma cruzi/aislamiento & purificación , Animales , Brasil/epidemiología , Carnívoros/parasitología , Enfermedad de Chagas/epidemiología , Reservorios de Enfermedades , Humanos , Marsupiales/parasitología , Roedores/parasitología , Triatominae/clasificación , Triatominae/parasitología , Triatominae/fisiología , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/genéticaRESUMEN
We studied the prevalence of Trypanosoma cruzi infection among eight species of wild small mammals (n=289) in an area where human cases of infection/disease have occurred. Dogs (n=52) and goats (n=56) were also surveyed. The study was carried out inside a biological reserve, the National Park 'Serra da Capivara' and its surroundings in Piaui State, Brazil. The marsupial Didelphis albiventris and the caviomorph rodent Trichomys apereoides were found to be the most important reservoirs in the study area. Trichomys apereoides was the most abundant species (80%) and D. albiventris the most frequently infected (61%). Both T. cruzi I and T. cruzi II genotypes were isolated from these species. One specimen of Tr. apereoides displayed a mixed T. cruzi I/zymodeme 3 infection. Serum prevalence among dogs suggests that they may be involved in the maintenance of the parasite in the peridomestic environment, in contrast to goats, which are not apparently of any epidemiological importance. The distinct distribution and patterns of infection observed in the study areas suggest that even in the same biome, epidemiological studies or determination of control measures must take into account ecological peculiarities.