Molecular characterization of Trypanosoma cruzi and infection rate of the vector Triatoma dimidiata in Costa Rica

Abstract

According to the genetic characterization by the analysis of the miniexon gene, strains of Trypanosoma cruzi can be classified into six discrete typing units (DTUs), and the DTU 1 into four distinct genotypes associated with different life cycles. While Chagas disease is endemic in Costa Rica, T. cruzi isolates from this region have never been genetically characterized. An analysis of 16 isolates from Costa Rica, based on miniexon gene analysis, showed the existence of two different haplotypes in the country, closely related to the Colombian haplotype group TcIa and to sequences from several Mexican isolates, with eight variable positions in the alignment and a variability of 2.6% between the compared sequences. No relationship between the habitat, vector or host, and the haplotypes was found, suggesting an active flow of T. cruzi in the country. The present study also reports a very high infection rate (47.3%, 26 out of 55 specimens) in a Costa Rican population of Triatoma dimidiata, the main vector of Chagas disease in this country. The distribution and abundance of the parasite and its main vector suggest a high risk of Chagas disease emergence in Costa Rica.

Canine trypanosomiasis in an endemic Costa Rican community: Demonstration of the active infection cycle

“…The same genetic variant of the T. cruzi parasite, the TcI lineage, was observed in both vectors and dogs in Getsemaní community, which agrees with previous studies that reports this lineage to be the most common in Central America (Zuriaga et al, 2012;Dorn et al, 2017). The finding of TcI in sympatric vectors and in dogs needs further studies in order to identify genotypic differences using more appropriate gene markers and assays with better sensitivity that could contribute to elucidate population dynamics (Izeta-Alberdi et al, 2016).…”

“…The most abundant and heterogeneous evolutionary lineage is TcI, which has been reported in triatomine vectors as well as in humans and wild and domestic animals, and this genotype has been found in both wild and domestic cycles (Muñoz et al, 2013;Padilla et al, 2017). This lineage has also been found in an opossum, a dog, eleven triatomines and three humans in Costa Rica (Zuriaga et al, 2012).…”

Uncovering vector, parasite, blood meal and microbiome patterns from mixed-DNA specimens of the Chagas disease vector Triatoma dimidiata

“…The identity of the second DTU is unclear, as it did not cluster with any of the DTUs for which sequenced reference genomes are available. The two DTUs most commonly found in Central America are TcI and, less frequently TcIV, for which a reference genome was not available (previously TcIIa) [ 72 – 78 ]. As additional references become available, the power of the RADseq mapping approach to positively assess DTU identities throughout the Americas should progressively increase.…”

The diversity of the Chagas parasite, Trypanosoma cruzi, infecting the main Central American vector, Triatoma dimidiata, from Mexico to Colombia

“…cruzi DTUs present in Triatoma dimidiata , the principal Chagas vector in Central America and a secondary vector in Mexico and northern South America. Of limited studies from this geographic region, most report the predominance of TcI and less frequent presence of TcIV [ 12 , 14 , 15 , 17 , 18 , 23 – 25 ]. A broader range of DTUs has also been reported in Mexico [ 26 , 27 ].…”