Thinking about intestinal parasites might be gut-wrenching for you, but understanding how pinworms reproduce and spread will at least help you avoid infection in the first place. They are among the most common human parasites in North America and around the world. Children are among the most commonly infected.
Pinworms rely on sexual reproduction -- they are not able to produce offspring asexually. A male and female worm must be present to create offspring, which is not the case with all worms. Reproduction among pinworms is often a self-destructive act. Male pinworms forcibly inject genetic material into females, an act known as traumatic insemination, which can cause physical damage to the females' bodies. Adult males are noticeably smaller than females, and they usually die shortly after a forcible mating session, according to the Parasites in Humans website. It takes about a month for the recently deceased male's genetic material to circulate through the female's body and fertilize the thousands of eggs contained within.
The Last Journey
After mating, females start a monthlong migration through the host's large intestine toward the only exit available. Females deposit their eggs near the host's perianal glands after emerging onto the surface skin, and they die shortly afterward. The emergence and egg-laying process irritates the skin around the host's anus, prompting the host to scratch the area. Female pinworms lay their eggs at night, so the skin irritation can lead to mild insomnia. The eggs are small enough to be transported through the air and thus inhaled, which can lead to ingestion and infection.
Life as an Egg
Pinworm infections begin and end with eggs. You or your kids can become infected by ingesting the parasite's eggs, which are invisible to the naked eye. Eggs can be transmitted between people as well as between shared objects, like door handles, clothes and toys. Pinworm eggs must enter the digestive tract to successfully infest a host. Touching your face or mouth after your hand has come into contact with an infected surface can put the pinworm eggs in a perfect spot to infiltrate your body. While pinworm infections aren't particularly dangerous for people, the eggs spread easily; it's possible to become reinfected after expelling the parasites through medical treatment.
Larvae, the Intermediary Stage
After a person accidentally consumes pinworm eggs, the tiny unborn parasites pass through the digestive tract until they reach the small intestine, according to the University of Chicago Pediatrics Clerkship. Larvae hatch from the eggs in the first part of the small intestine in a section known as the duodenum. The mobile larvae then migrate to the large intestine and anchor themselves on the organ's lining. They steal nutrients from their host so they can grow and mature over one to two months.
Ending the Infiltration
Basic personal hygiene is the most important preventative measure you can take to protect yourself of your family from a pinworm infection. Medications including ebendazole and pyrantel pamoate treat the disease. Follow your doctor's instructions on preventing and managing the infection if he determines pinworms are responsible for your discomfort. Pharmaceutical treatments are generally administered in two doses spaced two weeks apart, according to the Centers for Disease Control and Prevention. Sterilize toys, blankets, clothes and other items to eradicate remaining pinworm eggs.
Quentin Coleman has written for various publications, including All Pet News and Safe to Work Australia. He spent more tan 10 years nursing kittens, treating sick animals and domesticating semi-feral cats for a local animal shelter. He graduated from the University of Delaware with a bachelor's degree in journalism.