Seroprevalence of Trypanosoma cruzi (TC) and risk factors in Colima, Mexico.

INTRODUCTION The present study was conducted to estimate the incidence of seropositivity to anti-Trypanosoma cruzi antibodies and analyze potential risk factors in Colima, on the western coast of Mexico. METHODOLOGY Longitudinal studies of 209 subjects with negative serology in 1999 for anti-Trypanosoma cruzi antibodies by hemagglutination inhibition test were tested again in 2005. At the same time, 716 children under six years of age were surveyed serologically (total n = 925); the history of Trypanosoma cruzi infection was determined by the same hemagglutination inhibition test. The variables analyzed were age, sex, living in triatomine-infested places, type of community, quality of housing, presence of pets, and number of inhabitants per house. RESULTS Trypanosoma cruzi seropositivity in the period of six years was 22/925 cases, with a point prevalence of 2.73% and an adjusted rate of 7.3/1,000 person-years. The variable living in triatomine-infested areas showed association with seropositivity anti-Trypanosoma cruzi antibodies (RR: 5.5; 95% CI: 1.28-23.5). The remaining variables showed no significant association. CONCLUSIONS This study confirms the active transmission of Chagas disease in Mexico´s western-central region, which merits greater epidemiological surveillance and vector control, particularly in localities infested with triatomines.