Pinworm

• GeneralThe commonest intestinal parasite in children; the female comes out at night to lay.
• It is diagnosed with the adhesive tape test, applied to the perianal area on waking and before washing, because eggs almost never appear in the faeces.
• The eggs stay infective for several weeks in bedding, towels and dust, so treatment has to cover the whole household.
• It is the commonest intestinal parasite in developed countries, and affects school-age children above all.
• The cycle closes through the hands. The female comes out at night and lays her eggs around the anus; the itching leads to scratching, the eggs lodge under the fingernails and from there return to the mouth or pass to someone else.
• The eggs become infective within hours and survive for days in bedding, toys and dust, which makes reinfection within a family almost the rule.
• The classic diagnosis is the tape test: adhesive tape is applied to the perianal area in the morning and examined under the microscope.
• Apart from the night-time itching the infection is usually mild, but treatment has to be given to the whole household at once.

Habitat & environment

A parasite: the human large intestine

Sources consulted: https://es.wikipedia.org/wiki/Enterobius_vermicularis