Immunological sequelae of Trichinella spiralis infection in mice: effect of viability and route of BCG administration on nematode-induced immunopotentiation.

Mice were infected with 200 Trichinella spiralis 22 days preceding administration of 4 times 10-6 viable or heat-killed BCG. The effect of the route of BCG administration on the subsequent delayed hypersensitivity response to old tuberculin was investigated by injecting the bacteria either intravenously, intraperitoneally, or subcutaneously. Animals of the various groups were tested for delayed hypersensitivity footpad responses 28 days after BCG inoculation. Infection with T. spiralis was found to potentiate the ability of mice to respond to both viable and heat-killed BCG. In the case of heat-killed BCG, this potentiation appeared to be route dependent, since it could not be demonstrated when the bacilli were injected subcutaneously.