Human Pinworm
Enterobius vermicularis, Oxyuris spp.
Phylum Nematoda Family Oxyuridae
Formally known as Oxyuris vermicularis
Also known as seatworm and threadworm.

Humans are not the only animals to host pinworms (see below), but Enterobius vermicularis lives only on primates. It infects humans the world over, with an estimated 40 million+ infections in the US alone.

What's going on

The pinworm is a small (1 cm or less) white worm that lives in the intestinal tract of humans. Adult pinworms live in the colon, females crawling out through the anus to lay eggs while the host sleeps. These eggs can survive for about two weeks, even off the host, and infect their host by being swallowed. These eggs are small enough to pass unseen, and may even float through the air for short distances. Once swallowed, the larvae hatch in the small intestine, and upon maturity they move into the colon and large intestine. Retroinfection, when the larvae hatch on the anal skin and crawl into the rectum, may be possible. The cycle from ingestion to oviposition is about one month; Life span of an adult is about two months.

Infection, Symptoms, and Diagnosis.

Most infections appear in school-aged or younger children. Adults can easily become infected, but tend to have better sanitary habits. Needless to say, simple things like washing your hands will help to prevent infection.

Symptoms include:

  • Itching around the anus.
  • Sleep disturbance.
  • irritability.
If things get really bad, you may experience decreased appetite and weight loss. Females may also experience vaginal irritation. Possible complications include salpingitis and vaginitis. On the other hand, many infections are so mild that there are no noticeable symptoms.

Diagnosis can be done with a 'scotch tape test', in which a strip of scotch tape is pressed against the anus and inspected under a microscope for eggs. The high-tech medical version of this is the pinworm paddle, which works on the same principle. Because washing cleans off the eggs, this test is usually done after a night's rest, before bathing.

Treatment and Prevention

I don't have much to say about treatment; there are drugs that can help clear this up (mebendazole, pyrantel pamoate, pyrvinium pamoate, and piperazine, among others), ask your doctor. Folk medicine prescribes wormwood. Ginger is also used as a general remedy for intestinal worms. When treating for pinworm, it's usually good to treat other family members at the same time, particularly young siblings.

Prevention is pretty obvious: bathe often, especially just after waking; wash your hands, especially after using the bathroom, after changing a diaper, and before eating; change underwear each day; don't scratch your anus, and don't bite your fingernails if you do.

Pinworm in Other Animals

Pinworm infections in other animals, as far as I can find, are about the same as pinworm infections in humans. Different drugs to treat it, and some animals are bothered more than others, but the life cycle and effects are pretty much the same. The worms listed below are all of the Family Oxyuridae, and all are commonly called pinworms.

Syphacia obvelata = mouse.
Aspicularis tetraptera = mouse.
Syphacia muris = rat pinworm.
Syphacia mesocricetus = hamster pinworm.
Passalurus ambiguous = rabbit pinworm.
Dentostomella translucida = gerbil pinworm.
Oxyuris equi = horse pinworm.

Pin"worm` (?), n. Zool.

A small nematoid worm (Oxyurus vermicularis), which is parasitic chiefly in the rectum of man. It is most common in children and aged persons.


© Webster 1913.

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