Strongyloides ratti infections in rats. I. Immunopathology.

The elimination of adult parasites from the intestines of rats after a first and second infection of Strongyloides ratti was studied. Expulsion after a second infection was anamnestic, indication that the response is immunologic. Intestinal mast cell responses accompanied damage and expulsion of worms, the secondary mast cell response being more rapid but less intense that the first. Antithymocyte serum suppressed expulsion as well as both the intestinal mast cell and circulating eosinophil responses to primary infection.