Another 25 percent are free-living species found in soil or freshwater. Ten percent are parasites of plants. The remaining 15 percent are parasites of animals. Dog heartworms are nematodes. About 50 species of nematodes attack humans, and an estimated 98 percent of the human population has had a nematode infection at one time or another.
Pinworms are a common nematode infection in humans.
Another nematode, the trichina, is the source of trichinosis, a sometimes fatal infection caused by eating raw or undercooked pork or wild game. Liu was a member of a team of researchers led by Ralph Berry, an OSU entomologist. We were working with hundreds of nematodes from all over the world at the time. For a scientist confronting a new species, there are many questions to answer. We suspected it would be beneficial because the foredune area where Dr. Liu collected the specimens is a sandy, moist, cool habitat where beneficial nematodes are often found around the world.