Factores bióticos y abióticos que determinan la seroprevalencia de anticuerpos contra Trypanosoma Cruzi en el municipio de Palmar de Bravo, Puebla, México

Abstract

Objective. To establish the relationship between seroprev- alence for antibodies against Trypanosoma cruzi and its rela- tionship with biotic and abiotic factors. Material and Methods. A cross-sectional study was conducted between August 2000 and September 2001. The study population consisted of a simple random sample of 390 volunteers re- siding in Palmar de Bravo, Puebla, Mexico. Sample and data collection procedures included assaying antibodies against T cruzi with validated assays, and searching for domestic res- ervoirs and triatomine bugs. The relationship between biot- ic and abiotic factors with seropositivity was assessed. Statistical analysis was conducted using Kappa values for diagnostic tests; statistical significance was assessed with 2 x 2 tables, chi-squared test with Yates' correction, Fisher exact test, and odds ratios. Results. The seroprevalence of T cruzi infection in humans was 4%; in domestic reservoirs (horses, pigs, and dogs) only 10% of canine reservoirs were positive. Vector species recognized were T barberi and T pal- lidipennis, with a Dispersion Area Index and a Colonization Index of 55% and 40%, respectively. The most important risk factors associated with positive serology were altitude