Assessment of Trypanosoma cruzi seroprevalence and diagnostic evolution in Mexican blood banks: A systematic review.

Chagas disease (CD), caused by the flagellated protozoan Trypanosoma cruzi, remains one of the most persistent public health challenges in Latin America and, increasingly, in non-endemic regions due to global migration. While vector-borne transmission continues to be the predominant route in rural settings, transfusion has become a significant iatrogenic mechanism of T. cruzi dissemination, particularly in urban areas and within fragmented healthcare systems. This systematic review assesses T. cruzi seroprevalence and the evolution of diagnostic approaches in Mexican blood banks over the period 2005-2025. Nineteen studies were selected from bibliographic sources including PubMed and Web of Science. The review design reduces "analytical age bias" by prioritizing evidence generated using modern diagnostic technologies. Analysis of the included articles indicates limited geographic coverage: data were reported from 12 of the 32 Mexican states. In terms of diagnostic methodology, enzyme-linked immunosorbent assay (ELISA) was the predominant technique (94.4%), complemented by Western blot, immunofluorescence assay (IFA), indirect hemagglutination assay (IHA), and polymerase chain reaction (PCR). The study populations were predominantly male (82.8%), and sample sizes ranged from 120 to >515,000 individuals. Reported seroprevalence values in the reviewed literature varied from 0.03% to 4.3%, with a pooled calculated mean of 1.0% across published studies, contrasting with the official national baseline of 0.23% reported in CNTS hemovigilance datasets for 2024; together, these findings support the conclusion that T. cruzi continues to pose an active risk to blood safety in Mexico. Overall, the findings underscore the need for a shift toward active, targeted surveillance. Recommendations include universal implementation of external quality assessment programs coordinated through National Blood Transfusion Center quality controls and local validation of diagnostic platforms using regional isolates. These measures would help ensure that screening strategies reflect regional biological characteristics and strengthen transfusion safety against CD.