Presence of diverse discrete typing units of Trypanosoma cruzi, in Argentina

LOPEZ C P; BARBOZA S E; BALSALOBRE A; VICENTE M E; MARTI G A; CECCARELLI S

La Plata

Congreso; II Congress of the Latin American Society for Vector Ecology Control of endemic zoonotic and vector-borne emerging and re-emerging diseases: Current challenges in Latin America; 2022

Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity.Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one calledTcBat are used for strain typing. These DTUs are defined as sets of populations that aregenetically more related to each other than to any other evolutionary unit. The aim of thiswork is to survey the information available on the different DTUs of T. cruzi present inArgentina. The systematic review of the information was carried out mainly from bibliographicdata and from the database of triatomines distributed in Argentina, developed by theCEPAVE Triatomine Laboratory and uploaded on the GBIF platform. Data were extractedfrom the species of triatomines and mammals where the presence of DTU of T. cruzi wasfound. In addition, information about the temporal and geographic framework of the study -including country/province/locality and/or geographic coordinates-, the diagnostic method,the type of biological sample and the number of infected individuals was collected. About 366scientific works were examined between the years 1935 and 2017, of which 44 of themmention T. cruzi in their studies, all made in Argentina. Using optical microscopy as amethodology, infection by T. cruzi was not found in 20.45% of the cases analyzed. On theother hand, 22.72% of the works showed positive infection results in terms of seroprevalenceor percentage, while 11.36% did not mention the methodology used to arrive at the positiveinfection result. Finally, the presence of the different DTUs was determined in 11.36% of thetotal works. The mixed infections were the most frequent with a 45.75%, TcVI with a 17.7 %,TcI with a 14.88%, TcV with a 11,45%, and TcII and TcIII with a 2.85% each. Most of thesereports were found in the provinces of Chaco, Santiago del Estero and Tucuman. The vectorspecies infected with the diverse DTUs were Triatoma infestans with 70.83%, followed byTriatoma sordida and Triatoma eratyrusiformes with 12.5% and 16.66%, respectively. Theinformation found in wild mammals was scarce, finding mostly individuals included in theorders Carnivora, Rodentia, Cingulata and Didelphimorphia. This information is essential tounderstand the epidemiology of Chagas disease and so that through spatial analysis foundareas of higher vectorial risk, a fundamental tool for decision makers on this problem. Theneed to expand the information on the presence of the several DTUs is crucial, since the useof data such as prevalence or percentages of infection cannot be used to produce thesespatial patterns of risk of vector-borne diseases.