Worms - including symptoms, treatment and prevention

Worldwide, there are many worms that can infest the bowels of people, but most of them are not problems in Australia because of our climate and very good sanitation. Worms causing infection in people are parasites that live and breed mostly in the bowel (intestine). The most common worm in Australian children is the threadworm, Enterobius vermicularis, sometimes called the pinworm. Infection with other worms such as roundworms, hookworms and tapeworms is less common.

Threadworms are small, white, thread-like worms 2 to 13 mm long. They are most common in children, but anyone of any age can be affected. They are not fussy about who they infect and having them does not reflect on the hygiene of a child’s home.

How worms are spread

Threadworms are caught when someone swallows the worm’s eggs. The eggs hatch inside the bowel, where they live, then travel out through the anus (back passage) to lay their eggs on the skin there at night time. The eggs may be picked up on the fingers and transferred to the mouth if the child scratches their bottom or doesn’t wash their hands after going to the toilet. However, the eggs may fall off into bedding or clothing, or be wafted into the air, settling on many surfaces in the home or school. They can survive for up to 2 weeks in the environment and can easily be picked up and cause infection in other people. Domestic pets are not a source of infection.

Signs and symptoms

Symptoms of threadworm infection may include an itchy bottom, irritability and behavioural changes, but most people have no symptoms.


Occasionally, with heavy infections, the thin adult threadworms may be seen on the surface of freshly passed faeces. Sometimes the worms can be seen around the child’s anus, if examined with a torch at night time. However, the best method of diagnosis is by the ‘sticky tape test’. To do this, press some clear sticky tape onto the skin around the anus first thing in the morning, before wiping or bathing. Then place the tape onto a glass slide or put it in a specimen container, so that your doctor can have it examined with a microscope to see if any eggs have been picked up by the sticky tape.

Incubation period

(time between becoming infected and developing symptoms)

Symptoms of infection are associated with high worm numbers resulting from repeated infections and may not occur until several months after initial infection, if at all.

Infectious period

(time during which an infected person can infect others)

Spread is possible as long as worms are present.


A single dose therapy is usually effective and is given to the infected person and each family member at the same time. You can buy worm treatment from pharmacies, without a prescription. It is not necessary to treat children on a regular basis, just in case they have worms.


  • Exclusion of people with worms from childcare, preschool, school and work is usually not necessary. If there are loose bowel motions, exclusion should be for 24 hours after the diarrhoea has ceased.
  • Make sure children wash their hands after using the toilet and before eating.
  • Parents should seek medical treatment for infected children.
  • Change bed linen and underwear daily for several days after treatment. Normal hot water washing of clothes and bed linen will kill threadworm eggs.
  • Clean toilet seats and potties regularly.
  • Keep children’s fingernails short.

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