Six Foodborne Parasites to Avoid

May 7th 2016

Because most foodborne parasites are transmitted through ingestion of undercooked meats, cooking meat to a high-enough temperature to kill any parasites is crucial to staying uncontaminated. In addition, foodborne parasites can be transmitted through raw vegetables that have come in contact with contaminated animal feces and haven't been properly washed. Because contaminated foods often don't look any different from uncontaminated foods, excellent food preparation hygiene is vital to staying healthy.

Giardia Duodenalis

This single-celled parasite lives in human and animal intestines and is carried into food through the water supply. People catch it by eating undercooked meat from an infected animal, drinking contaminated water or eating anything that has touched a contaminated surface. Avoid giardia by drinking only treated water and cooking food to a safe internal temperature.


These microscopic protozoa cause a form of diarrhea known as cryptosporidiosis. The protozoa can live outside the body for an extended period of time and manages to live even when chlorine bleach is applied to it. It is most commonly carried in untreated water.

Toxoplasma Gondii

Toxoplasmosis, the disease resulting from infection by the Toxoplasma gondii parasite, can be extremely serious and even fatal for the elderly, pregnant women and people with weakened immune systems. Symptoms include muscle aches, flu-like symptoms and vision disturbances, all of which can last for months. This parasite is often carried in cat feces as well, so pregnant women should avoid or take special care when cleaning the litter box.

Cyclospora Cayetanensis

Ingesting this foodborne, single-celled parasite can result in symptoms that include explosive diarrhea, bloating, low-grade fever, loss of appetite and muscle aches as well as other uncomfortable digestive symptoms. The parasite is carried in infected food or water as well as in the stool of any animal or human who has ingested infected food. Washing hands frequently and drinking treated water prevent against catching cyclospora.


Trichinella cause trichinellosis, sometimes known as trichinosis. It's caused by the trichinella worm, which is passed on to humans when they eat undercooked or raw pork from a pig infected with the parasite. The infection, which can last several months, is characterized by nausea, vomiting, fever, cough and aching joints. A severe infection can progress to affect muscle coordination and the circulatory system, and it can be fatal.


Tapeworms are parasitic worms that transfer to humans who eat undercooked or raw pork or beef that is infected with the parasite. Once the tapeworms take up residence in a human intestine, they conduct a full life cycle, laying eggs that are then shed through the individual's feces, providing opportunities for others to contract the parasite. People can live with tapeworms for many years if they're not treated. Symptoms include abdominal pain, digestive disturbances and weight loss.


Parasites that cause foodborne illnesses can be microscopic, or they may be large enough to see with the naked eye. Oftentimes, parasites are transmitted to food in food processing facilities that don't practice adequate hygiene. About 48 million Americans contract a foodborne illness each year, and many of those are due to parasites in food. Here are some of the most common food parasites found in the United States.

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