Trypanosoma cruzi Transmission Cycle Among Wild and Domestic Mammals in Three Areas of Orally Transmitted Chagas Disease Outbreaks

Abstract

We report Trypanosoma cruzi infection in wild and domestic mammals from three orally acquired Chagas disease outbreak areas in Brazil. Cachoeiro do Arari (Pará) displayed a panzootic scenery (positive mammals in all ecologic strata), and human cases were probably the consequence of their exposure within the sylvatic T. cruzi transmission cycle. In Navegantes (Santa Catarina), Didelphis spp. was the main reservoir host, given that 93% were infected. In Redenção (Ceará), Monodelphis domestica and Thrichomys laurentius were also important for parasite maintenance. TCI was present in the three studied areas. Additionally, Z3 was detected in an armadillo from Pará and TCII in a triatomine from Navegantes. Domestic animals showed a high seroprevalence and should be considered sentinels in surveillance programs. The importance of a reduction in wild mammalian fauna diversity and selection of suitable T. cruzi reservoir hosts are discussed as risk factors for the re-emergence of Chagas disease.

2 nd Brazilian Consensus on Chagas Disease, 2015

“…cruzi is a multi-host flagellate parasite capable of infecting tens of species of wild and domestic mammals distributed in all phytogeographic regions in Brazil; it is found in the most diverse ecological niches, contributing, in each type of ecotope, to form singular modalities of natural transmission foci (21) (23) (27) (39) (78) (79) (80) . The integration of the reservoirs in the routine monitoring process should be taken into account given that domestic animals are not confined and can also act as a link between wild and domestic transmission routes (80) (81) . As with wild mammals, the importance of domestic animals (for example, dogs and cats) as reservoirs of T. cruzi varies in different places, and they can be used as sentinel populations of transmission of T. cruzi in a given area (21) (81) .…”

Seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en un área endémica de Venezuela

“…Los pájaros como fuente de alimento y los armadillos como reservorio, son animales que logran mantener los ciclos peridoméstico y selvático de la enfermedad de Chagas 38 .…”

High-Resolution Molecular Typing ofTrypanosoma cruziin 2 Large Outbreaks of Acute Chagas Disease in Colombia

“…This drought killed about 20 000 animals in the area and caused many of them to move from the sylvatic environment to the oil well surroundings in search of food and water, given that these were the only sources of water available in the area. This, coupled with the facts that didelphids are considered synanthropic reservoirs and that their presence in domestic habitats is considered a marker of environmental changes [1], explains the presence of opossums around the restaurant and specifically at the site where water and food were stored (Figure 2). A high rate of parasite infection among anal secretions from didelphids in Brazil and Colombia has been described elsewhere, implicating these secretions as a source of infection in several outbreaks of orally transmitted infection [1,4,15].…”

“…Additionally, qPCR detected the parasite in reservoirs, insects, and heart tissue from both patients who died, providing more information for analysis of possible sources of infection. Regarding the reservoirs, it is important that T. cruzi DNA was detected in all samples of blood and odoriferous gland secretions from the opossums, revealing didelphids as a potential source of infection; this reservoir has been described elsewhere as one of the main sources of T. cruzi infection in outbreaks related to oral transmission [1,4,8]. In addition, it is important to emphasize that, in both outbreaks, specimens from dogs tested positive by qPCR, indicating active transmission of the parasite from the sylvatic to the domestic environment.…”

“…T. cruzi has been classified into 6 discrete typing units (DTUs), TcI-TcVI, and, within TcI, into 2 genotypes (domestic TcI [TcI Dom ] and sylvatic TcI). In humans, this mechanism has been described in >1000 cases corresponding to 138 outbreaks, with a fatality rate of 8%-35% across Latin America [1,2]. In Colombia, between 1992 and 2009, 11 outbreaks were reported, with a lethality rate of 16.0% [3].…”