Survival of Onchocerca volvulus in nodules implanted in immunodeficient rodents.

Onchocerca volvulus is an obligate human parasite, and its study has been difficult due to an inability to maintain it outside the human host. We report the successful transplantation of onchocercomata containing living adult O. volvulus worms into immunodeficient C.B.-17.scid/scid (scid) mice or athymic rnu/rnu (nude) rats. Living, motile worms containing viable microfilariae were present in onchocercomata recovered from scid mice or nude rats for up to 20 wk, establishing a novel animal model for future investigation of O. volvulus.