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

LOPEZ, C; BARBOZA, E; BALSALOBRE, A; VICENTE, ME; MARTI G. A; CECCARELLI, S

La Plata

Congreso; II Congreso Latinoamericano de Ecología de Vectores (LA SOVE).; 2022

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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 called TcBat are used for strain typing. These DTUs are defined as sets of populations that are genetically more related to each other than to any other evolutionary unit. The aim of this work is to survey the information available on the different DTUs of T. cruzi present in Argentina. The systematic review of the information was carried out mainly from bibliographic data and from the database of triatomines distributed in Argentina, developed by the CEPAVE Triatomine Laboratory and uploaded on the GBIF platform. Data were extracted from the species of triatomines and mammals where the presence of DTU of T. cruzi was found. 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 366 scientific works were examined between the years 1935 and 2017, of which 44 of them mention T. cruzi in their studies, all made in Argentina. Using optical microscopy as a methodology, infection by T. cruzi was not found in 20.45% of the cases analyzed. On the other hand, 22.72% of the works showed positive infection results in terms of seroprevalence or percentage, while 11.36% did not mention the methodology used to arrive at the positive infection result. Finally, the presence of the different DTUs was determined in 11.36% of the total 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 these reports were found in the provinces of Chaco, Santiago del Estero and Tucuman. The vector species infected with the diverse DTUs were Triatoma infestans with 70.83%, followed by Triatoma sordida and Triatoma eratyrusiformes with 12.5% and 16.66%, respectively. The information found in wild mammals was scarce, finding mostly individuals included in the orders Carnivora, Rodentia, Cingulata and Didelphimorphia. This information is essential to understand the epidemiology of Chagas disease and so that through spatial analysis found areas of higher vectorial risk, a fundamental tool for decision makers on this problem. The need to expand the information on the presence of the several DTUs is crucial, since the use of data such as prevalence or percentages of infection cannot be used to produce these spatial patterns of risk of vector-borne diseases.