Intestinal Worms

Intestinal worms are common across the globe. Pinworms are the most common type of intestinal parasite in Canada. Pinworm infection, also known as oxyuriasis or enterobiasis, primarily affects children.

Signs and symptoms

While many people with pinworms do not have any symptoms, the most common symptom is itching around the anus. The itching occurs most often at night, leading to trouble sleeping and irritability. Some may also experience stomach pain, nausea and vomiting.

Transmission

Pinworms are highly contagious. Contamination occurs when an infected person scratches the affected area and gets eggs on their hands, which are then transferred to the mouth or food. Pinworm eggs can live up to three weeks at room temperature outside the body.

Detection and diagnosis

The female worm lays her eggs close to the anus, usually at night when the infected person is sleeping. The worms typically measure about 1 cm in length, and look like tiny white threads. Using a flashlight, you can examine the skin around the anus and collect worms and eggs by applying adhesive tape (Scotch tape) around the anus and folding the tape over itself. The sample can then be taken to the doctor where it can be looked at under a microscope. The worms may also be visible in the stool.

Treatment and prevention

Treatment of pinworms involves two doses of medication with the second dose given 2 weeks after the first dose. Since the medication does not kill the eggs, treatment must be repeated to kill any new adult worms that have developed from the eggs and larvae. Also, since pinworms spread easily from person to person, your health care professional will probably recommend that all family members be treated.

While the medication is effective, reinfection is common. In addition to the medication, the following measures should be taken:

• Take a shower every morning;
• Wash bedding often (every 3 to 7 days for 3 weeks);
• Wash pajamas, underwear and hand towels every day for 2 weeks;
• Wash hands often with soap and water. Pay special attention to the fingernails, especially before eating, after using the toilet and after touching the area around the anus;
• Keep nails short;
• In the week after the treatment, wear underwear at night and in the daytime and change them in the morning and at night;
• Avoid shaking the sheets and clothing before washing them so as not to spread the eggs;
• Wash the toilet often.

To relieve anal itching, use a cream or ointment such as zinc oxide-based products.