ANIMAL RESERVOIRS FOR TRYPANOSOMA-CRUZI INFECTION IN AN ENDEMIC AREA IN PARAGUAY

Animal reservoirs for Tryponosoma cruzi infection were investigated in 5 communities in the Department of San Pedro, currently one of Paragu ay's most highly endemic areas. A total of 112 domestic animals (37 ca ttle, 2 horses, 1 ass, 20 pigs, 44 dogs and 8 cats) and 4 wild animals (I white-eared opossum, 2 yellow armadillos and 1 common long-nosed a rmadillo) were examined for blood. Although no trypomastigotes were fo und by 2 direct observation methods, the microhaematocrit and Giemsa s tained thick and thin smears methods, several forms of trypanosoma fla gellates morphologically identical to T. cruzi were detected in the li ver infusion tryptose (LIT) medium from a single sample taken from a y ellow armadillo, Euphractus sexcintus. When serum samples of ail the a nimals were examined for antibody to T. cruzi by direct agglutination (DA) test, 3 cattle, 2 pigs, 16 dogs and 3 cats had positive titers (1 :32 or greater), but no wild animals showed positive reactions. T. cru zi was not found by culture nor microscopic examination of samples fro m any of the seropositive animals. However, domestic animals such as c attle, pigs, dogs and cats which were found to be seropositive in this study, possibly act as an animal reservoir in this endemic area as we ll as armadillos in which T. cruzi was observed.