Trypanosoma cruzi in Los Angeles and Miami blood donors: impact of evolving donor demographics on seroprevalence and implications for transfusion transmission.

Background: Trypanosoma cruzi, the agent of Chagas' disease, continues to be a concern for blood safety, as demonstrated by recent transfusion-transmitted cases in the United States and Canada. The chronic nature of Chagas', coupled with increasing numbers of immigrants from T. cruzi-endemic countries, suggests that Chagas' is a long-term public health problem.