Parasites can live in food or in water and can range in size from tiny, single-celled organisms to worms visible to the naked eye. An intestinal parasite lives in the intestine of a host, such as an animal or human being, and gets its food from, and often at the expense of, its host. The transmission of parasites can occur from animals to humans, from humans to humans or from humans to animals.
Contaminated Food
Consuming undercooked meat contaminated with an intestinal parasite can cause an infection, reports the United States Department of Agriculture. Types of meat that can carry intestinal parasites include beef, pork, lamb, chicken or wild game. Consuming contaminated fruits or vegetables that grew in soil containing an intestinal parasite can cause an infection as well.
According to the United States Department of Agriculture, several parasites have emerged as significant causes of food-borne illnesses. These organisms live and reproduce within the intestines of infected people and they excrete them in their feces. Infected people who don't properly wash their hands after having a bowel movement can spread parasites when they handle food. Unsuspecting people who eat the contaminated food product acquire the infection.
Contaminated Water
Transmission of an intestinal parasite can occur through contaminated water, states the Centers for Disease Control and Prevention. Drinking water from untreated or contaminated water supplies, including lakes or rivers, can cause an infection. Drinking unpasteurized milk, juices or cider can spread intestinal parasites too, notes the United States Department of Agriculture.
Pets
FamilyDoctor.org indicates that household pets such as dogs, cats, birds and reptiles can carry parasites. Infected pets can carry parasites in their urine, stool and saliva. Kissing a pet on the mouth and sharing food with them can cause intestinal parasites. Cats carry the intestinal parasite called toxoplasmosis in their feces. Placing the hands to the mouth after handling cat litter, garden soil or sandboxes where cats have defecated can cause this type of intestinal parasite, explains the United States Department of Agriculture. FamilyDoctor.org advises to limit, if possible, a cat's access to eating wild animals. Cats can develop toxoplasmosis from eating them.
FamilyDoctor.org recommends getting all household pets, when applicable, vaccinated and de-wormed. Vaccinating and de-worming pets decreases the chances of them developing intestinal parasites and then spreading an infection.
