Evaluation of immune dependence of anthelmintic treatment of Heligmosomoides polygyrus in CBA/Ca mice.

The efficacy of anthelmintic treatment of adult Heligmosomoides polygyrus was evaluated in immunologically intact and immune-incompetent (T-cell-deprived) CBA/Ca mice. There was no statistically significant difference in the cure rate, in terms of percentage reduction in worm burden, following treatment with pyrantel pamoate and levamisole between normal (57-71% reduction) and immune-incompetent mice (69-78% reduction). The rate of expulsion, and the total number, of worms expelled from infected mice following drug treatment were comparable in normal and deprived mice. The activity of 2 drugs against adult H. polygyrus has been shown to be independent of the immune status of the host. The significance of the mode of actions of drugs and the site of residence of a parasite within the host are discussed.