Chronic myocardial damage in experimental T. cruzi infection of a New World primate, Cebus sp. monkey

American trypanosomiasis and Chagas disease: Sexual transmission

OBJECTIVE

To contribute to the discussion on the research findings indicating the sexual transmission of American trypanosomiasis and Chagas disease in humans.

METHODS

A review of the literature was performed to investigate the routes of transmission of Trypanosoma cruzi parasites and to evaluate the distribution of Chagas disease, which is now found across five continents.

RESULTS

The epidemiological profile of American trypanosomiasis, which is still considered a neglected disease of the poor people of Latin America, has changed over time. A family-based study demonstrated that the blood protozoan T. cruzi can be transmitted sexually from infected males and females to naïve mates.

CONCLUSIONS

Evidence that Chagas disease can be transmitted sexually, coupled with the migration of individuals with Chagas disease to previously non-endemic countries and increased travel to endemic countries, has implications for public health. Improved screening of blood supplies and prenatal care are required to prevent congenital spread.

Clinical, biochemical, and electrocardiographic aspects of Trypanosoma cruzi infection in free-ranging golden lion tamarins (Leontopithecus rosalia)

BACKGROUND

Wild golden lion tamarins from the Biological Reserve of Poço das Antas, Rio de Janeiro, Brazil, have high prevalence of Trypanosoma cruzi infection leading us to clinically assess the disease in this endangered species.

METHODS

34 tamarins were sampled for the presence of T. cruzi infection (through serology) and clinical evaluation (electrocardiography, blood counts and biochemical analysis).

RESULTS

32% of the sampled tamarins were T. cruzi positive, 45% of these displayed cardiac abnormalities. Main cardiac abnormality in infected tamarins was T wave low voltage; R wave low voltage and V3S wave high voltage were also found. The tamarins displaying T wave low voltage had high proportion of seric cardiac creatine kinase. Seric mean total protein was significantly higher in infected tamarins.

CONCLUSIONS

Sampled tamarins displayed typical signs of T. cruzi infection, similar to experimentally infected primates and human natural infection. Potential risk of T. cruzi infection to this endangered species is discussed.

The Syrian hamster as a model for the dilated cardiomyopathy of Chagas’ disease: a quantitative echocardiographical and histopathological analysis

Chronic Chagas' disease cardiomyopathy (CCC) is caused by the protozoan Trypanosoma cruzi, and it affects 30% of the 16-18 million people infected in Latin America. A good rodent model that develops a dilated cardiomyopathy closely resembling human CCC after T. cruzi infection is still needed. We compared the cardiomyopathy developed by T. cruzi-infected Syrian hamsters with human Chagas' disease cardiomyopathy using quantitative methods. Female hamsters were infected with 3.5 x 10(4) (G1, n = 10) or 10(5) (G2, n = 10) T. cruzi Y strain blood trypomastigotes. Control animals (C, n = 10) were injected with saline solution. Cardiac function was assessed by echocardiography at 4, 8 and 12 months post-infection. Heart sections were submitted to histopathological/morphometric analysis 12 months post-infection. At this time, ventricular dysfunction and diffuse or multi-focal myocarditis were observed in 91% and 100% of G1 and G2 infected groups, respectively. Median interstitial collagen volumes in groups C, G1 and G2 were 1.2%, 1.9% and 3.9%, respectively, and were significantly higher in group G2 than in group C. Among infected animals, myocarditis showed a positive correlation with interstitial fibrosis. Deaths in the chronic phase (8-12 months post-infection) were more frequent among G2 than G1, and were associated with macroscopic ventricular dilation, severe myocarditis and increased fibrosis values, along with an earlier onset of ventricular dysfunction. The T. cruzi chronically infected Syrian hamster develops a cardiomyopathy which resembles human Chagas' disease cardiomyopathy, and might be an adequate tool to investigate pathogenic mechanisms of this disease and to search for novel therapeutic strategies.

Gastric acid secretion response in the Cebus apella. A monkey model of chronic Chagas' disease

The objective was to study the secretory pattern, both basal and stimulated either by histamine (0.1 mg/kg) or pentagastrin (64 micrograms/kg) in eighteen Cebus apella monkeys chronically infected with different T. cruzi strains (CA1, n = 10; Colombian, n = 4 and Tulahuen, n = 4) and to describe the morphological findings in the gastrointestinal tract in twelve infected (6 sacrificed and 6 spontaneously dead) and four healthy monkeys. All infected monkeys and 35 healthy ones were evaluated by contrast X-ray examination. No differences were observed in basal acid output between control and infected groups. Animals infected with the Tulahuen and Colombian strains showed significant lower values of peak acid output in response to histamine or pentagastrin (p < 0.01 and p < 0.05 respectively; "t" test) in comparison to the controls. Barium contrast studies showed enlargement and dilatation of the colon in three infected animals. Histopathological lesions were seen in 75% of the autopsied animals either in colon alone (33%) or both, in colon and esophagus (42%). The normal secretion observed in the CA1 infected group could be due to a lower virulence of the strain, a lower esophageal tropism or the necessity of a longer post-infection time to cause lesions.