Transmission
Pinworms enter your body when you swallow their eggs. One female pinworm may expel thousands of eggs into the environment. As the eggs are moist and rather resistant to drying, they can infect humans even after being distributed in dust for several days.
The female pinworm deposits her eggs in the area around your anus. You can expose yourself to the infective eggs by scratching the contaminated area. The eggs then attach to your fingertips and from there go into your mouth. When you swallow, the eggs travel to your intestines.
The eggs also may be scattered into the air from bed linen and articles of clothing. They are capable of clinging to surfaces such as bedding, clothing, toys, doorknobs, furniture, and faucets for up to 2 weeks.