Nematode Parasites in Humans

Nematodes, also known as roundworms, are very abundant in nature and outnumber insects. Nematodes species are either parasitic or free-living and feed on bacteria. Parasitic nematodes that most commonly infect humans are filarial worms, whipworms, horsehair worms, Ascaris and hookworms.

Types

• According to the Cleveland Clinic, Enterobius vermicularis causes enterobiasis, Ascaris lumbricoides causes ascariasis, Ancylostoma and Necator cause ancylostomiasis and Trichinella spiralis causes trichinosis. These are the most common roundworm parasites that infect humans.

Infection

• The most common mode of infection is when a person swallows roundworm eggs. Contamination occurs through manual transfer of the eggs through feces, soil, dust or other parts of the environment. Hookworms enter the skin directly, usually through soil. Filarids enter the skin through fly bites.

Symptoms

• Roundworm infection symptoms depend on the species of roundworm but include diarrhea, itching around the infected area, difficulty sleeping, abdominal pain or even blindness. You may identify eggs or worms in the stool or on skin that surrounds the anus.

Treatment

• Treatment is dependent on the type of infection. Treatment types include prescription or over-the-counter medications that vary by dosage.

Prevention

• Maintain proper hygiene: wash hands frequently with soap and water, cook or wash raw produce before eating, avoid walking barefoot in soil, wear clean undergarments and bathe frequently.