Macracanthorhynchus

A genus of giant thorny-headed worms (class Acanthocephala). [macro- + G. akantha, thorn, + rhynchos, snout]

- M. hirudinaceus the giant thorny-headed worm of the pig, approximately the size of the giant roundworm (Ascaris); it inhabits the intestinal tract where nodules develop at the site of penetration of the spiny proboscis of each worm; it has occasionally been reported in man; transmission is by ingestion of infected insects, frequently dung beetles or cockroaches that have fed on feces of infected pigs containing viable eggs and have developed the cystacanth stage infective to the vertebrate host, including humans.

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Mac·ra·can·tho·rhyn·chus -'riŋ-kəs n a genus of intestinal worms of the phylum or class Acanthocephala that include the common acanthocephalan (M. hirudinaceus) of swine

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Mac·ra·can·tho·rhyn·chus (mak″rə-kan″tho-ringґkəs) a genus of acanthocephalans. M. hirudinaґceus is parasitic in pigs in the United States, and occasionally humans. M. inґgens is a common intestinal parasite of raccoons in North America, and has been found in one human case.