Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

Abstract

Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela.

Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal

“…2010; Carrasco et al . 2012) and is ubiquitous among sylvatic transmission cycles across the parasite's endemic range (Llewellyn et al . 2009a).…”

Distantiae Transmission of Trypanosoma cruzi: A New Epidemiological Feature of Acute Chagas Disease in Brazil

“…This successful parasite species is found from the southern United States to Argentinean Patagonia [3]. Trypanosomiasis due to T. cruzi is characterized as a complex zoonosis, transmitted by approximately 130 species of triatomines from the Reduviidae family (Hemiptera insects that are exclusively hematophagous at all life stages) and able to infect more than 150 species of wild and domestic mammals in 8 orders [4].…”

The crucial role of the Instituto Evandro Chagas in Chagas disease research

“…The aim was to obtain a deeper understanding of the molecular epidemiology of Chagas disease and the extent and implications of genetic exchange in T. cruzi. The international collaborators produced a large body of relevant published work, and an assessment of the wider geographical distributions and ecological associations of the six genetic lineages of T. cruzi 26,27,28,29,30,31,32,33,34 ( Figure 7). Most recently, this work has included the development of peptide-based T. cruzi lineage-specific serology for discovery of the reservoir hosts of TcII, TcV and TcVI 35,36 .…”

“…Most recently, this work has included the development of peptide-based T. cruzi lineage-specific serology for discovery of the reservoir hosts of TcII, TcV and TcVI 35,36 . This later research is beyond the scope of the current text but updates can be found in key recent reviews or by searches with appropriate keywords in PubMed [26][27][28][29][30][31][32][33][34] . Although the IEC was not directly involved in ChagasEpiNet, it was the research at the IEC, in conjunction with subsequent developments in molecular technologies that provided the platform for the productive ChagasEpiNet international initiative.…”