INFECTION WITH TRYPANOSOMA-CRUZI DURING PREGNANCY IN RATS AND A DECREASE IN CHRONIC MYOCARDIAL LESIONS IN THEIR INFECTED OFFSPRING

To ascertain whether maternal infection with Trypanosoma cruzi may inf luence the course of the parasitic infection in offspring, two groups of female 1 rats were mated with syngeneic sires. One group of females was infected with 10(6) trypomastigotes of T. cruzi three times at we ekly intervals. All offspring were nursed by their mothers until weani ng and then separated into two groups of young, one to be infected wit h the same dose of T. cruzi, and the other to remain uninfected. Infec tion of pregnant rats caused no aggravated disease but resulted in a s elf-controlled infection that did not cause any deaths or affect their reproductive capacity. The number of young delivered, litter size, fe rtility coefficient, and offspring weights at weaning were also unaffe cted by maternal infection; however, the survival coefficient decrease d in comparison with values recorded in the offspring of uninfected mo thers. The latter finding is likely due to neonatal transmission, sinc e bloodstream forms of T. cruzi were observed in a few offspring of in fected mothers. While infected offspring whose mothers had been inocul ated with T. cruzi during pregnancy were not protected from acute infe ction, the occurrence of chronic focal myocarditis was less prevalent when compared with that recorded in chronically infected offspring bor n to uninfected mothers.