The most common type of human worm infection in Australia is pinworm. Other names for this parasite include threadworm and Enterobius vermicularis
, or the common term ‘worms’.
Children are more likely to pick up an infection than an adult, probably because of children’s tendency to put their fingers in their mouths. However, once a child is infected, other members of their household are also likely to get pinworms unless strict hygiene practices are observed. Despite the unsavoury reputation, a pinworm infection is relatively harmless and can be easily treated.
Worms require a host in order to survive. In the case of pinworms, the human acts as the host.
Life cycle of a pinworm
Infections begin when pinworm eggs are eaten, usually directly through contaminated hands or indirectly through contaminated food, bedding, clothing or other articles. The eggs then travel to the gut where they hatch and mature. A grown pinworm is yellowish white, slender and about one centimetre long.
Around four weeks after ingestion, the adult female moves down the gut and exits the body via the anus to lay a batch of eggs on the surrounding skin, often at night. The worm then dies, her reproductive mission complete.
The eggs may cause intense itching, especially at night, so children can easily reinfect themselves by scratching the anus and scraping eggs under their fingernails. These eggs can then be transferred to the mouth and the whole life cycle of the pinworm starts again. The eggs can survive for several days in the right conditions.
Symptoms of pinworm
Pinworm infections often produce no symptoms but, when they occur, symptoms can include:
- itchy bottom, especially at night
- reduced appetite
- feeling mildly unwell
- inflammation of the vagina
- adult worms can sometimes be seen in the faeces, and eggs may be seen clinging to the skin around the anus
- irritability and behavioural changes.
Treatment for pinworm infection
Your doctor might want to perform a test to make sure the problem is a pinworm infection. This is done by collecting the eggs from around the anus using sticky tape first thing in the morning. Medication is available to kill the worms and this is usually prescribed for the person who is infected and all other members of the household. Usually, one dose is followed up with a second dose two weeks later to take care of any surviving worms.
Although the medication is safe for humans, you should consult your doctor or chemist before commencing treatment.
Preventing another pinworm infection
Suggestions to prevent another infection during treatment include:
- All family members should wash their hands and nails thoroughly with soap and water, particularly after going to the toilet, after changing nappies, before preparing food and before eating food.
- Discourage scratching of the bottom and nail biting.
- Keep fingernails short.
- Daily bathing and showering.
- Wash all sheets, bed linen, pyjamas and sleepwear in hot water to kill any pinworm eggs.
- Clean the toilet seat regularly with disinfectant (remember to store the disinfectant out of reach of children).
- All family members should take the medication, regardless of whether they are experiencing symptoms.
Where to get help
Things to remember
- Pinworm is the most common worm infection in Australia.
- The major symptom is an itchy bottom, particularly at night.
- Treatment usually includes a two-dose course of medication that should be taken by all members of the affected household.
- If symptoms persist, consult your doctor.
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Communicable Disease Prevention and Control Unit
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.