Human coenurosis in North America: case reports and review.

Coenurosis is a zoonotic disease of humans caused by the larval stage of Taenia (Multiceps) species. In North America, the adult tapeworm of Taenia (Multiceps) serialis is found in canids. The cystic larval forms (coenuri) are found in hares, rabbits, squirrels, and, rarely, in humans. We review in clinical detail the fifth case reported from North America, involving a child with extensive central nervous system involvement. We also report a sixth case, involving an adult with an intramuscular coenurus. The latter case was diagnosed by needle aspiration of the cyst. Although praziquantel administration may have been effective in killing the parasite in both patients, we are concerned about the production of marked inflammation as a result of treatment. The four other North American cases are reviewed, and the epidemiology of the infection in animals is discussed.