Presence of Anti-T. cruzi Antibodies in Inhabitants and Dogs of Two Rural Settlements in the Sierra de Los Tuxtlas, Veracruz, Mexico.

PURPOSE: The aim of this study was to identify the risk factors associated with house infestation by Triatoma dimidiata as well as with Trypanosoma cruzi infection in humans and owned dogs in two rural communities from the municipality of Catemaco, Veracruz, Mexico. METHODS: One hundred and 16 human blood samples and 34 dog blood samples were collected. The presence of anti-T. cruzi antibodies was determined using four different ELISA assays. Moreover, reactive ELISA sera from humans and dogs were processed by indirect immunofluorescence (IFI) to confirm the presence of anti-T. cruzi antibodies. RESULTS: Serologic tests for T. cruzi infection showed a prevalence of 5.1% (6/116) in humans and of 50% (17/34) in owned dogs. CONCLUSION: The presence of animals (dogs, chickens and wild animals), as well as some characteristics of house construction were identified as risk factors for infestation and infection. Complementary studies must be carried out to allow a better understanding of the transmission dynamics in the state of Veracruz, Mexico, and the implementation of adequate control programs.

Natural infection with Trypanosoma cruzi in three species of non-human primates in southeastern Mexico: A contribution to reservoir knowledge.

The mechanisms of infection and dispersion of Trypanosoma cruzi among animals, especially in the sylvatic environment, are still not entirely clear, and various aspects of the transmission dynamics of this parasite in the sylvatic environment are still unknown. T. cruzi is a parasite with a great biological and genetic diversity that infects a wide variety of hosts, therefore, transmission cycles of this parasite are complex. The objective of this study was to determine the prevalence of T. cruzi infection and analyze the genetic variability of the discrete typing units (DTUs) of the parasite in three non-human primate species (Alouatta palliata, Alouatta pigra, and Ateles geoffroyi) in southeastern Mexico. A total of one hundred sixty-four serum samples (42 samples of A. pigra, 41 samples of A. palliata (free-ranging) and 81 samples of A. geoffroyi (hosted in care centers)) were analyzed for the detection of anti-T. cruzi antibodies by ELISA assays. The seroprevalence of infection was 23.39% in A. palliata, 21.40% in A. pigra and 16.27% in A. geoffroyi. Additionally, presence of parasite DNA was assessed by PCR, and the identification of DTUs was performed by real-time PCR coupled to High Resolution Melting (qPCR-HRM). Different DTUs (TcI, TcII, TcIII, TcV and TcVI) were found in the analyzed monkeys. In addition, infection of monkeys was not associated with age or gender, but it was associated with the species. This study reveals the risk of infection in the study area and that the different DTUs of the parasite can coexist in the same habitat, indicating that T. cruzi transmission in the study area is very complex and involves many ecological factors. However, there is a need for long-term studies of host-parasite interactions to provide a solid understanding of the ecology of these species and to understand the dispersion strategies of T. cruzi.

Presence of Seropositive Patients to Trypanosoma cruzi in a Municipality of the Mixtec Sierra of the State of Puebla: A Preliminary Study.

PURPOSE: The state of Puebla has the social marginalization and ecological conditions for the transmission of infectious agents to be effective. Until a few years ago, the state of Puebla was considered non-endemic to the presence of Trypanosoma cruzi as there are no official reports of chronic cases. The objective of this work was to carry out a preliminary study on the prevalence of anti-T. cruzi antibodies in rural areas of the Huatlatlauca municipality in the Mixtec sierra of the state of Puebla. METHODS: A total of 196 serum samples from 12 rural localities were tested by using four tests: two enzyme-linked immunosorbent assays, an xenodiagnoses and PCR assay. RESULTS: Overall, 28 (14.2%) of 196 samples were positive for T. cruzi by ≥ 2 tests (95% CI 6.6-20.8%). Our results suggested that the municipality of Huatlatlauca in the Mixteca Sierra of the state of Puebla is an area with endemic potential for the disease with a high prevalence rate in the adult population and with cases in newborns, these high transmission rates are probably associated with problems of congenital and vector transmission. CONCLUSION: Additional studies should be conducted to generate adequate campaigns for the control of Chagas disease in this area.

Codetection of Trichomonas vaginalis and Candida albicans by PCR in urine samples in a low-risk population attended in a clinic first level in central Veracruz, Mexico.

The aim of this study is to estimate the prevalence of Trichomonas vaginalis and Candida albicans in low-risk patients treated at a first level clinic (primary health care represents the first level of contact of individuals, families, and the community with the system national health). Using a cross-sectional study in patients treated in clinical laboratory of the Sanitary District no. 7 of the city of Orizaba during the months June-July, 252 urine samples were collected for the identification of T. vaginalis and C. albicans by PCR. Furthermore, we analyzed the sociodemographic characteristics of the studied population. We observed an overall prevalence of 23.41% (95% CI 22.10-24.72) for T. vaginalis and 38.88% (95% CI 37.73-40.03) for C. albicans. There was also presence of coinfection in 14.28% (95% CI 13.10-15.46), which was associated with the presence of pain. Most of the positive cases were observed in women house-maker (80%, 95% CI 50.36-48.98). The results of this study provide evidence that the majority of positive cases observed in the studied population are presented in an asymptomatic form and usually are not associated with any risk factor.