Detection and genotyping of Trypanosoma cruzi from acai products commercialized in Rio de Janeiro and Para, Brazil

Background: Several cases of food-borne acute Chagas disease (ACD) have been reported in the Brazilian Amazon so far. Up to 2004, the occurrence of ACD by oral transmission, associated with food consumption, was rare. Recent cases of ACD in Brazil have been attributed to the consumption of juice from the acai palm containing reservoir animals or insect vectors waste, infected with Trypanosoma cruzi. This study aimed to determine the T. cruzi contamination rate and to genotype the parasite in food samples prepared from acai, which are commercialized in Rio de Janeiro and the Para States in Brazil. Methods: The amplificability of DNA extracted from acai samples, and T. cruzi and Triatominae detection were performed by conventional PCR. Molecular characterization was done by multilocus PCR analysis, to determine the parasite discrete type units (DTUs) based on the size of PCR products in agarose gels, using the intergenic region of the spliced leader (SL), 24 Sa rDNA and nuclear fragment A10 as targets. Results: From the 140 samples of acai-based products analyzed, T. cruzi DNA was detected in 14 samples (10%); triatomine DNA was detected in one of these 14 samples. The parasite genotyping demonstrated that food samples containing acai showed a mixture of T. cruzi DTUs with TcIII, TcV and TcI prevailing. Conclusions: In this study, the molecular detection and identification of T. cruzi from acai-based manufactured food samples, was performed for the first time. Although parasite DNA is a marker of possible contamination during food manufacturing, our findings do not indicate that acai is a source of Chagas disease via oral transmission per se, as live parasites were not investigated. Nevertheless, a molecular approach could be a powerful tool in the epidemiological investigation of outbreaks, supporting previous evidence that acai-based food can be contaminated with T. cruzi. Furthermore, both food quality control and assessment of good manufacturing practices involving acai-based products can be improved, assuring the safety of acai products.