Effect of the expulsion phase of Trichinella spiralis on Hymenolepis diminuta infection in mice.

The rapid elimination of the intestinal phase of Trichinella spiralis in NIH mice is associated with progressive inflammation of the intestinal tract. The non-specific effects of this inflammation were studied in mice concurrently infected with an unrelated parasite, Hymenolepis diminuta, which does not stimulate a visible inflammatory response but is also immunologically rejected by this strain of mice. It was demonstrated that the rejection phase of T. spiralis infection had a marked effect upon the growth and survival of H. diminuta. The cestode either failed to establish or to grow; if the worms were already strobilate when inflammation developed then destrobilation occurred. There was no cross-immunity between the parasites, nor was the interaction a direct consequence of inter-specific competition.