Infection by Trypanosoma cruzi in mammals in Yucatan, Mexico: a serological and parasitological study

Abstract

In order to determine Trypanosoma cruzi infection among mammals in Yucatan, Mexico, 372 animals, both wild and synanthropic including carnivores, marsupials and rodents were studied. Serological studies by indirect haemagglutination (IHA) were carried out to detect antibodies to T. cruzi and a parasitological study was also performed (blood smear and histopathology). Of all the animals tested 18.54% were serologically positive, with a significantly higher frequency among the wild ones (33.33%) compared to the synanthropic ones (17.79%). To determine T. cruzi in positive animals, blood was inoculated into a white mouse (webster type) to prove myocardium colonization. The serological and parasitological positivity of these animals, as well as their behavior in the environment, taken together with the socioeconomic and cultural characteristics of the population, suggest that in Yucatan, Mexico, Canis familiaris, Didelphis marsupialis and Rattus rattus act as a link with the wild cycle.

The opossum Didelphis virginiana as a synanthropic reservoir of Trypanosoma cruzi in Dzidzilché, Yucatán, México

“…This study confirmed Gardner's (1973) fear that no external morphological characters reliably differentiate D. virginiana from D. marsupalis, and highlighted the need of karyotyping in areas of sympatrical distribution of these Domínguez et al 1990, Zavala-Velázquez et al 1996, Solís-Franco et al 1997. As reported (Jones et al 1974) we observed the dominance of D. virginiana population over D. marsupialis (96:2).…”

“…In this area, D. marsupialis and D. virginiana are sympatric, however, their specific importance as reservoir is not well established. Even though, D. virginiana is thought to be the most abundant opossum species in northern Yucatán (Jones et al 1974), only D. marsupialis has been found infected with T. cruzi (Zavala-Velázquez et al 1996).…”

Update on Chagas' disease in Mexico

“…Seroprevalence of T. cruzi infection in these reservoirs has been reported to vary between 8% to 62% according to species and regions. [42][43][44][45] Together, these vector and reservoir studies clearly demonstrate that T. cruzi infection is a zoonosis endemic in many regions of Mexico. The importance of human infection and disease is, on the other hand, more difficult to establish.…”

High Frequency of Human Blood in Triatoma dimidiata Captured Inside Dwellings in a Rural Community in the Yucatan Peninsula, Mexico, but Low Antibody Seroprevalence and Electrocardiographic Findings Compatible with Chagas Disease in Humans

“…In this cycle of transmission, several reservoirs are involved: infected Didelphys virginiana and Peromyscus leucopus have been found in the sylvan cycle, and in the peridomestic and domestic cycles, Canis familiaris, Rattus rattus, Mus musculus, and humans have been found at different rates. [7][8][9] The precise epidemiological role of T. dimidiata in human infection in the Yucatan peninsula should be addressed.…”