Effect of mode of infection on the development and chemotherapeutic response of Hymenolepis nana in rats.

The susceptibility of rats to Hymenolepis nana (Cestoda) and the chemotherapeutic response of anti-cestode drugs was studied during egg-inducted and cysticercoid-induced infections. In cysticercoid-induced infection, the percentage of infected animals and the number of mature worms were significantly more than in egg-induced infection. The former mode of transmission required more drug to clear the parasites. These differences have been discussed on the basis of immunity engendered in the definitive host by the developing larvae.