Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

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

Molecular epidemiologic source tracking of orally transmitted Chagas disease, Venezuela.

Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing

PCR-RFLP genotyping profiles of Venezuelan <i>Trypanosoma cruzi</i> strains.

<p>Each pair of lanes shows undigested PCR product followed by restriction digest products for GPI (A) and HSP60 (B). Loading order, left to right: 1, BAJV104; 2, XPMPDM5; 3, VE1003; 4, VE3303; 5, BACR104; 6, BAJT104; 7, PARAMA13; L(A), Hyperladder I (Bioline, UK); L(B), Hyperladder V (Bioline, UK).</p

Reference strains used in this study.

<p>Reference strains used in this study.</p

Oligonucleotide primers employed in this study.

<p>Oligonucleotide primers employed in this study.</p

Distribution of <i>Trypanosoma cruzi</i> Discrete Typing Units (DTUs) in Venezuela.

<p>The three maps display samples collected from humans (top left), vectors (top right), and mammal reservoirs (bottom left). Pie chart area is proportional to sampling size. Pie segment colour represents DTU identity. Inset on each map shows the capital (Caracas) and surrounding states in greater detail.</p

Geographical distribution of <i>Trypanosoma cruzi</i> genotypes from different hosts in Venezuela.

**<p>Morphological and molecular identification.</p>*<p>Morphological identification only.</p

RAPD profiles of representative circulating Venezuelan <i>Trypanosoma cruzi</i> strains.

<p>Loading order, left to right <b>A</b>: 1, CanIII cl 1 (TcIV); 2, Esmeraldo cl2 (TcII); 3, WA250 cl 10B (TcI); 4, 8839(TcIV); 5, 8196(TcIV); 6, 10141(TcI); 7, 10610(TcIV); 8, 8089(TcI); 9, 6872(TcI); 10, PGN23(TcI); 11, PGN27(TcIV); 12, PGN31(TcI); L, 1 kb DNA Ladder. <b>B</b>: 1, CanIII cl1 ; 2, Esmeraldo cl2; 3, WA250 cl 10B; 4, 11932; 5, 7082; 6, 8104; 7, 7570; 8, 7780; 9, SJ1097; 10, pgn2; 11, PGCHG; 12, CD45.</p

Isoenzyme profiles of GPI and PGM from representative circulating Venezuelan <i>Trypanosoma cruzi</i> strains.

<p>Loading order, left to right: TcI, WA250 cl 10B; TcII, Esmeraldo cl2; TcIV, CanIII cl 1; 1, 8839(TcIV); 2, 8196(TcIV); 3, 10141(TcI); 4, 10610(TcIV); 5, 8089(TcI); 6, 6872(TcI); 7, PGN23(TcI); 8, PGN27(TcIV); 9, PGN31(TcI).</p