Trypanosoma cruzi infection in the opossum Didelphis marsupialis: Absence of neonatal transmission and protection by maternal antibodies in experimental infections
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