Pinworm

What are pinworms? 

Enterobius vermicularis is a small thin white roundworm (nematode) that lives in the large intestine. While an infected person sleeps, female pinworms leave the intestine through the anus and deposit their eggs on the surrounding skin.

Signs and symptoms

• Most people have no signs or symptoms
• Itching and irritation around the anal or vaginal area
• There is the potential for a secondary infection of scratched sites
• Noticeable worms seen in the perianal region two to three hours after child goes to sleep

Incubation period

One to two months (or longer) from the ingestion of an egg until the adult females are noticeable in the perianal region

Contagious period and spread

Pinworm infections are spread through direct transfer of eggs through the fecal→oral route, or indirectly through clothing, bedding, food, or other articles contaminated with the parasite eggs. A dust-borne infection is possible in heavily contaminated areas.
A person is infectious as long as eggs are present on the perianal skin. Eggs remain infective in an indoor environment for about two to three weeks.

Public health reporting requirements

• Individual cases are not reportable to public health.
• Report the infection to the facility director or school nurse. 
• If more than one child is ill, refer them to a physician and contact public health as this may be an outbreak.

Control of spread

• Educate children and staff on good personal hygiene, particularly the need for handwashing before eating and food preparation.
• Keep fingernails as short as possible.
• Make sure those infected with pinworms, as well as household contacts and caregivers, are receiving proper treatment.
• Daily bathing in the morning with showers or stand up baths is recommended over sit-down bathing in a bathtub. Co-bathing children should be avoided. 
• Frequent changing of underclothing, night clothes, towels, and bedding. 
• Launder clothing, towels, and bedding in hot water daily for several days post-treatment.
• Clean home/daycare/classroom daily for several days post-treatment.
• Consult with local or state public health for help with implementation of control measures.

Treatment

There are appropriate anti-worm medications that will be prescribed by a physician, which are taken two weeks apart. Control is difficult in child care centers and schools due to high reinfection rates. In such situations, mass and simultaneous treatments, repeated in two weeks, may be effective.

Exclusion

• EXCLUDE infected individuals from food preparation until cleared by a physician.
• Children/students and staff with pinworm infection should not otherwise be excluded.

Role of teachers, caregivers, and family

• Suspect pinworms if a child has intense itching around the anal or vaginal area.
• Avoid shaking bedding or underwear to prevent spreading eggs through the air.
• Wash toys frequently, and clean and sanitize surfaces used for eating, toileting, hand hygiene, food preparation, and diapering.