The high rate of natural Trypanosoma cruzi
infection found in opossums does not always correlate with appreciable densities of local triatomid populations. One alternative method which might bypass the invertebrate vector is direct transmission from mother to offspring. This possibility was investigated in
five T. cruzi infected females and their litters (24 young).
The influence of maternal antibodies transferred via
lactation, on the course of experimental infection, was also
examined. Our results show that neonatal transmission is
probably not responsible for the high rate of natural T. cruzi
infection among opossums.
In addition antibodies of maternal origin confer a partial
protection to the young. This was demonstrated by the finding
of a double prepatency period and 4, 5 fold lower levels of
circulating parasites, in experimentally infected pouch young
from infected as compared to control uninfected mothes. On the
other hand, the duration of patent parasitemia was twice as
long as that observed in the control group.