This paper attempts to prove if a high Trypanosoma cruzi
prevalence of opossums might be reached with few potential
infective contacts.
One non-infected Didelphis albiventris to T. cruzi and 10
infected nymphs of Triatoma infestans were left together
during 23 hr in a device that simulated a natural opossum
burrow. Twenty-six replicates were performed using marsupials
and triatomines only once. Potentially infective contacts
occurred in all the trials. From the 26 opossums used in
trials, 54% did not eat any bug. Of the 260 bugs used, 21%
were predated. In the 25 trials involving 205 surviving bugs,
36% of them did not feed. In 15/25 cases, }/= 60% of the
triatomines were able to feed.
The parasitological follow-up of 24 opossums showed that among
10 that had eaten bugs, 4 turned out infected and among the 14
that had not predate, 3 (21%) became positive. In sum, 7/24
(29%) of the marsupials acquired the infection after the
experiment. This infection rate was similar to the prevalences
found for the opossum population of Santiago del Estero,
Argentina, suggesting that the prevalences observed in the
field might be reached if each marsupial would encounter
infected bugs just once in its lifetime.
