a1 London School of Hygiene and Tropical Medicine, London, WC1E 7HT
Trypanosomes are consistently present in the milk of lactating mice with primary phase T. cruzi infections (Peru strain). The infection is transmitted to the young, although rarely, mainly due to the difficulty of establishing infection via the oral route. Lactating females which had recovered from the primary phase of T. cruzi infection consistently transferred antibody to their young during suckling. The antibody in the serum of the young and milk of the mother was detectable by the indirect fluorescent antibody technique. In the case of the Peru strain the presence of antibody transferred to the young in this way correlated with very good protection against T. cruzi. Antibody transferred to the young was no longer detectable 6 weeks after birth. The indirect fluorescent antibody technique using bloodform antigen proved specific and highly sensitive throughout, giving prolonged and comparably high titres in mice infected with chronic and acute strains of T. cruzi.
(Received September 06 1971)