Specific cutaneous hypersensitivity responses in mice infected or immunized with Trypanosoma cruzi.

The appearance and development of cutaneous hypersensitivity to epimastigote antigen was followed during the early phase of Trypanosoma cruzi infection in mice. The effect of living BCG on the kinetics of skin reactivity was studied in animals infected with T. cruzi blood trypomastigotes or artificially immunized with disrupted epimastigotes. BCG stimulated the immediate response in infected animals while preferentially stimulating delayed responses in immunized animals. Infection with living blood trypomastigotes depressed already existing delayed-type responses. The development of delayed-type responses was also impaired in animals immunized in the course of the infection.