Evidence of Trypanosoma cruzi infection (Chagas' disease) among patients undergoing cardiac surgery

Background-Trypanosoma cruzi, the agent of Chagas' heart disease, is transm itted by triatomine insects and by blood transfusion. The emigration of sev eral million people from T cruzi-endemic countries to the United States has raised concerns regarding a possible increase in cases of Chagas' heart di sease here, as well as an increased risk of transfusion-transmitted T cruzi . To investigate these 2 possible outcomes, we tested a repository of blood specimens from multiply transfused cardiac surgery patients for antibodies to T cruzi. Methods and Results-Postoperative blood specimens from 11430 cardiac surger y patients were tested by enzyme immunoassay, and if repeat-reactive, were confirmed by radioimmunoprecipitation. Six postoperative specimens (0.05%) were confirmed positive. Corresponding preoperative specimens, available fo r 4 of these patients, were also positive. The other 2 patients had undergo ne heart transplantations. Tissue samples from their excised hearts were te sted for T cruzi by polymerase chain reaction and were positive. Despite th e fact that several of these 6 patients had histories and clinical findings suggestive of Chagas' disease, none of them were diagnosed with or tested for it. Patient demographics showed that 5 of 6 positive patients were Hisp anic, and overall, 2.7% of Hispanic patients in the repository were positiv e. Conclusions-No evidence for transfusion-transmitted T cruzi was found. All 6 seropositive patients apparently were infected with T cruzi before surger y; however, a diagnosis of Chagas' disease was not known or even considered in any of these patients. Indeed, Chagas' disease may be an underdiagnosed cause of cardiac disease in the United States, particularly among patients born in countries in which T cruzi is endemic.