Pinworms are contracted when you eat food, touch anything, or touch anyone infected with pinworm eggs and then put your fingers into your mouth. Once the eggs enter the intestines, they mature and hatch in your intestine. Female pinworms exit your intestines from your anus and lay their eggs on nearby skin.  Adult pinworms are white and less than an inch long, or about the length of a staple. They migrate at night to the anus and lay their eggs there. They can lay up to 10,000 eggs. It only takes a few hours for the pinworm eggs to hatch and become capable of causing infection. Pinworm eggs can survive for up to two weeks on clothing, bedding, food, and other surfaces. Pinworm eggs can survive for two weeks on pet fur, but only humans can be infected. Children under the age of 18 are at the highest risk for pinworms. It has been estimated that 10 to 40% of all children have had pinworms at one time or another. Young children are at the highest risk for pinworm infection, along with their household members and caretakers.  Children can unknowingly spread pinworms within their household. If your child has pinworms, you should treat everyone in the household because there is a high risk that the child unknowingly spread the infection. Children can also spread pinworms at school or in daycare centers. Unfortunately, most of the time a pinworm infection is asymptomatic, so the infected person has no idea he is infected. If the person does show signs and symptoms of an infection, the main sign of pinworm infection is itching around the anus. This especially occurs at night when the females are laying the eggs and the eggs are hatching. The itching can be severe, and your child may be very uncomfortable. Other symptoms may include urinary tract infections and sleep loss.  Infection can occur if the patient scratches very hard and opens the skin. You can diagnose pinworm infections at home using a tape test, but you still should have your child seen by his or her physician.

TL;DR in Chinese:
了解人是如何感染蛲虫的。 识别危险因素。 识别蛲虫感染的体征症状。