Pinworm (Enterobius vermicularis) Transmission

Pinworms are primarily transmitted through the fecal-oral route, where eggs from an infected person are ingested by a susceptible individual. 1

Primary Modes of Transmission

Fecal-oral route is the main mode of transmission for pinworms, where microscopic eggs are transferred from the anus to the mouth 1
Autoinfection occurs when a person scratches the perianal area due to itching caused by female worms laying eggs, then transfers eggs to their mouth via contaminated hands 2, 3
Eggs can contaminate bedclothes, underwear, hands, and food touched by contaminated hands 2
Airborne transmission can occur as pinworm eggs are lightweight and can become airborne, allowing them to be inhaled or ingested when floating in the air 2, 4
Fomites such as toys, countertops, door handles, and other objects can be contaminated with pinworm eggs and serve as vehicles for indirect transmission 1

Children aged 5-14 years show the highest prevalence of pinworm infection 3
Poor personal hygiene, especially inadequate handwashing after using the toilet and before eating 1, 3
Nail-biting and finger-sucking behaviors increase risk of transmission 3, 5
Overcrowded living conditions facilitate transmission between individuals 3
Shared sleeping spaces increase risk of exposure to eggs 2, 3

Nocturnal perianal itching (pruritus ani) is the most common symptom 1, 6
Many infections (approximately 30-40%) are asymptomatic 3
Other symptoms may include weight loss, irritability, diarrhea, abdominal pain, and occasionally colitis with eosinophilia 1, 6
Female genital tract colonization can occur, causing vaginal discharge 1, 7

Frequent handwashing with soap and water, especially after using the toilet and before eating 2, 3
Regular cleaning of bedroom floors by vacuuming or damp mopping to remove eggs 2
Washing bed linens and night clothes regularly without shaking them (to avoid dispersing eggs) 2
Keeping toilet seats clean 2
Keeping fingernails short and discouraging nail-biting and finger-sucking behaviors 3, 5
Wearing tight underwear both day and night, and changing it daily 2
Treatment of all household members simultaneously to prevent reinfection cycles 3, 5

The "sellotape test" (adhesive tape test) is the preferred diagnostic method, performed by applying adhesive tape to the perianal region in the morning to collect eggs 6
Multiple tests (ideally three) performed on different mornings increase sensitivity from 50% to approximately 90% 3
Direct visualization of adult worms in the perianal area, particularly at night, can aid in diagnosis 6
Stool examination is generally not recommended as pinworms and eggs are not usually passed in the stool 3

First-line treatment options include:
- Albendazole 400 mg as a single oral dose 1, 6
- Mebendazole 100 mg as a single oral dose 1, 2
- Pyrantel pamoate (11 mg/kg, maximum 1 g) as a single oral dose 3
Treatment should be repeated after 2 weeks to address reinfection from eggs that may have hatched after initial treatment 6, 3
Treatment of all household members should be considered, especially with multiple or repeated infections 3, 5