Trypanosoma cruzi: seroprevalence detected in the blood bank of the Instituto Nacional de Pediatria, Mexico City, in the period 2004 through 2009

BACKGROUND: The second most common mode of Trypanosoma cruzi or Chagas disease transmission is via therapeutic blood transfusion. In Mexico, control of T. cruzi is still in its initial phase; in fact, there are only 14 studies published covering 10 states on T. cruzi seroprevalence in donated blood in Mexico. Here we present the results of 5 years of trypanosomiasis screening in the blood bank of the Instituto Nacional de Pediatria. STUDY DESIGN AND METHODS: Samples from all blood donated in the period from 2004 to 2009 were analyzed. We screened for T. cruzi using an enzyme-linked immunosorbent assay technique. Seropositive samples were then processed using the polymerase chain reaction (PCR) to detect a nuclear gene segment. RESULTS: A total of 37,333 samples were analyzed and a 0.17% (64 samples) T. cruzi seroprevalence was found. Donors were mostly from Mexico State and Mexico City, which is considered nonendemic for T. cruzi area. Of 64 seropositive samples, only two tested positive by PCR (3.12%), which amplified a 189-bp product from nuclear gene from the parasite. CONCLUSION: Although the seroprevalence of T. cruzi infection was low, this surveillance program prevented the infection of more than 100 children because each unit of blood provides 2.6 to 3.5 blood products. The majority of the donors were from Mexico State and Mexico City, which is a nonendemic area. The serodetection of T. cruzi in this region is evidence that is necessary to increase our understanding of its distribution in the Mexico City and surrounding places.