Enterobius vermicularis

Enterobius vermicularis	Contents	Rev 07-09-2025
Pin worm; Threadworm	Classification
	Morphology and Anatomy	Life Cycle
Return to Enterobius Menu	Distribution	Ecosystem Functions and Services
	Feeding	Management
Return to Oxyuridae Menu	Biology and Ecology	References
	Go to Nemaplex Main Menu	Go to Dictionary of Terminology

Classification:

Chromadorea Chromadoria

Rhabditida

Spirurina

Oxyuroidea

Oxyuridae

Enterobius vermicularis Linnaeus, 1758

Morphology and Anatomy:

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Prevalence differs widely in different regions of the world. Personal hygiens, hand-washing are important avoidance tactics. Infections can be especially prevalent in young children playing on the ground.

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Feeding:

Enterobius vermicularis is an intestinal parasite of humans. Usually found in the intestinal lumen but occasionally in the intestine wall or in tissues outside the intestinal tract.

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Hosts:

Different species of Enterobius are parasites of humans, chimpanzees, orangutangs, monkeys, loris, and others. E. vermicularis is the species predominant in humans.

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Life Cycle:

Pinworm parasites of vertebrates.

In E. vermicularis, the entire life cycle, from egg to adult, takes place in the intetine of a single host between 2 and 8 weeks.

There are four molts; the first two within the egg before hatching and two before becoming adults.

Larvae hatching from eggs grow rapidly to lengths of +/- 150 microns and migrate through the small intestine to the colon.

Females survive up to 13 weeks and males about 7 weeks. Mated females establish feeding sites in the mucosa of the intestine. The body of the gravid female becomes filled with 11,000 to 16,000 eggs. The females migrate to the host rectum and anus where they release eggs and then die.

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

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Damage:

The parasitic disease in humans is known as enterobiasis or oxyuriasis. Usually not very dangerous and often asymptomatic. Soemetimes infections occur in the pelvic region or urinary tract of women.

The most typical symptoms are itching in the perianal region, especially at night, caused by migration of egg-laying adults.

May cause symptoms similar to appendicitis.

Cook, G.C. 1994. Enterobius vermicularis infection. Gut 35:1159-11c2