Prevalence of Chagas heart disease in a region endemic for Trypanosoma cruzi: evidence from a central Bolivian community.

BACKGROUND

Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population.

OBJECTIVES

We sought to determine the current prevalence of T. cruzi infection and associated Chagas heart disease in a Bolivian community endemic for T. cruzi.

METHODS

Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or electrocardiogram consistent with cardiac abnormalities were also scheduled for echocardiography.

RESULTS

Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% vs. 0% for complete right bundle branch block and 10.4% vs. 1.9% for any bundle branch block; p = 0.008 and p < 0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure.

CONCLUSIONS

Though almost one-third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease.