Role of adult worms in immunity of rats to Nippostrongylus brasiliensis

Abstract

Immunity to N. brasiliensis in rats is stimulated primarily by the adult worms. An initial infection consisting solely of adult worms terminated at the same time as an infection consisting of all the parasitic stages.Immunity is not stage specific. Immunity stimulated by adult worms acts not only on adult stages inhibiting their reproduction but also inhibits the development to maturity of larvae in a challenge infection.Rats infected solely with female adult worms, whether egg producing or sterile, are more resistant to reinfection than rats infected with male worms only.Immunity stimulated by a single normal infection lasts a long time but it does not depend on the persistence of adult worms in the intestine of the rats.This work was done during the tenure of a Commonwealth Scholarship awarded by the Association of Commonwealth Universities.