Intestinal worms are parasitic organisms that reside within the human digestive system. Understanding how they are acquired is the first step toward effective prevention. This article explains the common ways people get intestinal worms and the situations that increase risk.
Common Intestinal Worms
Several types of intestinal worms can affect humans. Pinworms, also known as threadworms, are small, white, and thin. They are among the most common worm infections globally, particularly affecting children.
Roundworms, specifically Ascaris lumbricoides, are another prevalent type, sometimes reaching up to a foot in length. Hookworms are intestinal, blood-feeding parasites named for the hook-like shape of their head, which they use to attach to the intestinal wall. Tapeworms are flat, ribbon-like worms that can grow quite long.
How Worms Enter the Body
Worms enter the human body through ingesting their microscopic eggs or larvae, or by direct skin penetration. Pinworm infections occur when a person swallows pinworm eggs, often transferred from contaminated hands or surfaces. Female pinworms lay their eggs around the anus, causing itching, and scratching can easily transfer these eggs to fingers.
Roundworm eggs are ingested from contaminated soil or food. Contaminated soil or food, often due to poor sanitation, can lead to ingestion of eggs. Once swallowed, eggs hatch and mature into adult worms.
Hookworms primarily enter the body when larvae penetrate the skin, often when walking barefoot on soil contaminated with human feces. After penetrating the skin, the larvae travel through the bloodstream to the lungs, migrate up the respiratory tract, are swallowed, and eventually reach the small intestine where they mature.
Tapeworm infections result from consuming undercooked meat or fish that contains tapeworm larvae cysts. Eating undercooked pork, beef, or certain fish introduces larvae into the digestive system, where they attach to the intestinal wall and grow into adult tapeworms. Tapeworm eggs can also be ingested from contaminated water, food, or animal feces.
Situations That Increase Risk
Certain environmental and behavioral factors increase the risk of intestinal worm infections. Poor sanitation and inadequate hygiene practices, such as not washing hands after using the toilet or before eating, are major contributors to spread. For pinworms, close contact with infected individuals and sharing personal items facilitates transmission.
Contact with contaminated soil, especially for children playing outdoors without shoes, increases hookworm infection risk. Unwashed produce or unsafe water can also introduce worm eggs or larvae. Eating raw or undercooked meat and fish risks tapeworm infections, as these foods harbor larvae.
Living in or traveling to regions with a high prevalence of intestinal worms and poor sanitation infrastructure increases risk. These conditions make accidental ingestion or skin penetration more probable.
Steps to Avoid Worms
Preventing intestinal worm infections involves implementing practical hygiene and food safety measures. Handwashing with soap and water is a primary defense, especially after using the toilet, changing diapers, and before handling food or eating. This practice helps remove microscopic eggs that may have been picked up from contaminated surfaces or through direct contact.
Ensuring safe food preparation is another preventive step. Meats and fish should be cooked thoroughly to kill any potential larvae, and fruits and vegetables should be washed well before consumption. Drinking safe, treated water and avoiding potentially contaminated sources can also prevent the ingestion of worm eggs or larvae.
Wearing shoes when outdoors, particularly in areas where soil might be contaminated with human or animal feces, helps prevent hookworm larvae from penetrating the skin. Proper disposal of human waste is also crucial in preventing the contamination of soil and water sources, thereby interrupting the life cycle of many intestinal worms. Regular deworming for pets, if applicable to specific worm types that can be transmitted to humans, can also contribute to a safer environment.