Serological determination of Trypanosoma cruzi in northern region of the State of Mexico.

Chagas disease, caused by Trypanosoma cruzi, remains a significant public health problem in Mexico, particularly challenging to diagnose during its chronic phase, due to low parasitemia and the complex immune response. According to the Pan American Health Organization, no single test is sufficiently sensitive or specific to reliably detect chronic Chagas disease, requiring the use of multiple serological methods when results are inconclusive. This study aimed to assess the seroprevalence of Chagas disease in the largely uncharted municipalities of the North of State of Mexico. A total of 250 serum samples from 17 municipalities were analyzed using a comprehensive approach involving three serological tests: the BIO-CHAGAS commercial kit (MEXLAB®), an ELISA test with antigens derived from an endemic strain, and a confirmatory Western blot analysis. The results revealed that 240 samples were negative, 3 were inconclusive, and 7 were positive, yielding a seroprevalence rate of 2.8% (7/250). The endemicity demonstrated in the municipalities of Hueypoxtla and Tequixquiac, combined with the documented presence of the vector Triatoma barberi in these areas, suggests an ongoing risk of T. cruzi transmission. These findings underscore the urgent need for targeted public health interventions, including increased surveillance, community awareness, vector control programs, screening tests to identify cases, and prompt treatment, to curb the spread of Chagas disease in this region.