Enterobiosis (infection of the colon)

Description of Pinworm Infection

This is a disease caused by parasitic worms, characterized by intense itching in the anal area, perineum, and symptoms of digestive system damage.

Causative Agent

Pinworm infection is caused by the contact helminth – Enterobius vermicularis (pinworm), which parasitizes the human lower small intestine and upper large intestine. In the uterus of fertilized females, 5-17 thousand eggs mature, and when they fail to attach to the intestinal mucosa, they crawl down the intestine due to intestinal movements. Some of them are eliminated with feces, while others lay eggs in the folds of the anal opening during nighttime. In the human body, invasive larvae mature within 6 hours and, when ingested, can start a new cycle. Eggs in the environment (bedding, on toys, in the bathroom, on the toilet) can survive for 1-3 weeks.

Prevalence

Pinworm infection is common in countries with poor hygiene practices and in closed groups of children, mental health patients. The highest incidence is among children aged 5-10 years. The source of infection is infected individuals, especially asymptomatic carriers of pinworms. Infection occurs by ingesting mature eggs. The infection is transmitted through dirty hands, towels contaminated with pinworm eggs, bedding, toys, and food.

Symptoms

The disease occurs 2-4 weeks after pinworm invasion. After infection, the first weeks may present with abdominal pain, more frequent bowel movements, itching, vomiting. A hallmark symptom of pinworm infection is nighttime itching in the anal area and interrupted sleep. General symptoms include fatigue, weakness, irritability, insomnia, indigestion, nocturnal enuresis, and teeth grinding. Pinworms often cause inflammation of the external genitalia and vagina in girls – vulvovaginitis. Rarely, worm infestation can lead to inflammation of the fallopian tubes, appendicitis.

Diagnosis

Pinworms can be seen during bowel movements, detected around the anus, and in underwear. However, for a definitive diagnosis, laboratory confirmation is necessary by examining scrapings from the folds around the anus under a microscope. The sample is taken with a cotton swab or adhesive tape early in the morning before bathing and bowel movements.

Treatment

It is essential to avoid reinfection, especially by properly washing the buttocks and anus with soap in the morning. The first-choice anthelmintic drug is mebendazole, with alternatives being albendazole and pyrantel pamoate. All medications are taken as single doses, repeated after 2 weeks. Contacts should also be treated simultaneously.

Prevention

It is necessary to educate all family members or individuals in a group affected by the disease to follow hygiene practices: wash hands before eating and after using the toilet, iron bedding and nightclothes. Patients should wash the perineum, anus, and genitalia with soap every morning, thoroughly clean undergarments, trim nails short, sleep wearing underwear. Clothing and bed linens should be washed in hot water.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology