[Biotic and abiotic determinants of seroprevalence of antibodies against Trypanosoma cruzi in Palmar de Bravo, Puebla, Mexico].
OBJECTIVE
To establish the relationship between seroprevalence for antibodies against Trypanosoma cruzi and its relationship with biotic and abiotic factors.


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 residing in Palmar de Bravo, Puebla, Mexico. Sample and data collection procedures included assaying antibodies against T. cruzi with validated assays, and searching for domestic reservoirs and triatomine bugs. The relationship between biotic 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. borberi and T. pallidipennis, 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 (>2,150 and <2,180 meters above sea level), presence of triatomines, age, time of residence, and participation in a social assistance program.


CONCLUSIONS
T. cruzi infection was identified in human beings, vectors, and possibly in domestic reservoirs, in communities located over 2,000 meters above sea level.
Sosa-Jurado
Francisca
F
Hospital de especialidades, Centro Médico Nacional Manuel Avila Camacho, Instituto Mexicano del Seguro Social, Puebla, Puebla, México.
Zumaquero-Ríos
José Lino
JL
Reyes
Pedro A
PA
Cruz-García
Abel
A
Guzmán-Bracho
Carmen
C
Monteón
Victor M
VM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D004197:Disease Reservoirs; D005260:Female; D006801:Humans; D007303:Insect Vectors; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D014349:Trypanosoma cruzi / Q000276:immunology*
D000913:Antibodies, Protozoan