Infecção pelo Trypanosoma cruzi em Canis familiares e Triatomíneos (Hemiptera, Reduviidae, Triatominae) na zona rural do Estado do Rio Grande do Norte

Abstract

The infection by Trypanosoma cruzi in Canis familiaris and Triatomines was evaluated in the home and peridomiciliary environment of rural communities in the State of Rio Grande do Norte. Blood samples from 43 dogs from rural areas in the municipalities of Acari, Caicó, Caraúbas and Marcelino Vieira were evaluated for T. cruzi infection by serological techniques and by Polymerase Chain Reaction (PCR) to identify T. cruzi kDNA. Serology was initially performed to identify anti-T.cruzi antibodies by ELISA (Enzyme-Linked Immuno Sorbent Assay) for IgM and IgG in house and the Indirect Immunofluorescence (IFR) reaction. The presence of anti-Leishmania antibodies with DPP® (Dual Path Platform, Bio-Manguinhos / FIOCRUZ) and ELISA were also used. The catches of triatomines were carried out in the same locations and in the same period in which the dog samples were collected and the infection evaluated by direct examination and/or PCR. The criterion for positivity in T. cruzi serology was the agreement between two different techniques, which resulted in 16.3% (7/43) of the samples suggestive of acute phase and 11.6% (5/43) of chronic phase. The reactive serology for Leishmania was 9.3% of the animals in the four municipalities studied, being more reactive in the municipalities of Acari. These results of reactivity for Leishmania and T. cruzi may be related to the overlap of endemic areas. In the identification of kDNA by PCR in blood samples from dogs, 41.9% (18/43) of the samples present the band 330pb, of these 6.8% (4/43) are in the municipality of Acari, 2.3% (1/43) in Caicó, 20.9% (9/43) in Caraúbas and 9.3% (4/43) in Marcelino Vieira. The catches of triatomines identified adults and nymphs of T. brasiliensis, T. pseudomaculata, R. nasutus and adults of P. lutzi in peridomiciliary and/or intradomiciliary environments of all the studied localities. The analysis of the intestinal contents evaluated by PCR found positivity of 78.5% (95/121) of the triatomines that cohabitated these environments with the dogs. The natural T. cruzi infection was identified in dogs and triatomines in all municipalities studied, probably helping to maintain active T. cruzi infection in the domiciliary area and increasing the risk of infection in the human population.