The revised Trypanosoma cruzi subspecific nomenclature: Rationale, epidemiological relevance and research applications

Abstract

The protozoan Trypanosoma cruzi, its mammalian reservoirs, and vectors have existed in nature for millions of years. The human infection, named Chagas disease, is a major public health problem for Latin America. T. cruzi is genetically highly diverse and the understanding of the population structure of this parasite is critical because of the links to transmission cycles and disease. At present, T. cruzi is partitioned into six discrete typing units (DTUs), TcI-TcVI. Here we focus on the current status of taxonomy-related areas such as population structure, phylogeographical and eco-epidemiological features, and the correlation of DTU with natural and experimental infection. We also summarize methods for DTU genotyping, available for widespread use in endemic areas. For the immediate future multilocus sequence typing is likely to be the gold standard for population studies. We conclude that greater advances in our knowledge on pathogenic and epidemiological features of these parasites are expected in the coming decade through the comparative analysis of the genomes from isolates of various DTUs.

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease

“…Our results showed that using two molecular markers was not sufficient for typing of T. cruzi isolates. These limitations were also observed by other authors 32,[60][61][62][63] . However, the use of three genetic markers with different evolutionary rates was able to ensure the correct typing of T. cruzi isolates.…”

“…Although TcII was identified in most T. cruzi isolates, no correlation with clinical forms was observed using rDNA 24Sα, COII, and SL-IR markers and polymorphisms in microsatellite analysis 32 . TcII has been reported as the primary cause of acute ChD and is the typical genotype detected in patients with cardiac and digestive forms of ChD, confirming the association of this DTU with human infection in Brazil and Argentina 57,63 . TcII has also been detected using the same markers with high homology among different hosts and locations in northeastern semiarid 62 .…”

“…TcII has also been detected using the same markers with high homology among different hosts and locations in northeastern semiarid 62 . TcI is associated with human infection in the Amazon, the Andean region, Central America, Mexico, and endemic areas of Southeastern and Northeastern Brazil [63][64][65][66][67] . Few cases of human infection caused by TcI have been described in Brazil 63,68 .…”

“…TcI is associated with human infection in the Amazon, the Andean region, Central America, Mexico, and endemic areas of Southeastern and Northeastern Brazil [63][64][65][66][67] . Few cases of human infection caused by TcI have been described in Brazil 63,68 . However, recent findings have detected TcI in patients with the indeterminate form of ChD in the northern region of Minas Gerais State 32 and in patients with cardiac, digestive, and indeterminate forms of ChD from Rio Grande do Norte State 69 .…”

Mother-to-Child Transmission of Trypanosoma cruzi

“…T cruzi parasites are composed of 6 genetic lineages (discrete typing units TcITcVI) [39]. All of the T cruzi lineages have been observed in congenitally infected infants with the exception of TcIV [40][41][42].…”