Foodborne parasitic infections are common, affecting at least 12 million people in the United States and more than 2 billion people worldwide. However, such infections often go undiagnosed due to poor awareness of these common microorganisms.
Foodborne parasitic infections often stem from protozoa or intestinal worms getting inside the digestive tract via contaminated water, food, or exposure to feces. It’s vital to practice good hygiene, adopt food safety strategies, and know which foods to avoid with parasites.
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Common Types of Parasites in Food
Parasites need a host to survive, grow, and spread. About 25% of the population worldwide has a parasite-related infection. The most common types of parasites found in foods are:
Protozoa
Protozoa are microscopic, one-celled organisms that can live in the intestines. Protozoa spread via contaminated water or food, insect bites, and person-to-person contact. Tens of thousands of types of protozoans exist, including:
Ciliates: ciliates, including B. coli, contain short, hairlike structures that allow these parasites to gather food and move.
Amoeba: amoebas, including E. histolytica, use false feet used to move.
Sporozoans: sporozoans, such as cryptosporidium and plasmodium, don’t move on their own but eat the digested food or body fluids of their host.
Flagellates: flagellates, including giardia and toxoplasma, use whip-like structures to move and explore their surroundings.
Helminths
Helminths are parasitic worms that can live in the gastrointestinal (GI) tract, including the stomach and small and large intestines. Parasitic worms may be visible to the naked eye.
Examples include:
Tapeworms: flat, long worms that live in the intestines and feed off nutrients in their host’s food. The eggs they lay spread through infected water or foods like undercooked fish, beef, and pork.
Flukes: flatworms that spread via aquatic animals (crabs, fish, snails, etc.), aquatic plants, and contaminated water.
Roundworms: parasites that live in the intestines and spread via foods (particularly pork), infected soil, and feces.
Pinworms: threadlike worms that spread through eggs in feces.
Ascaris: worms that resemble tiny earthworms and spread via contaminated soils and produce grown in these soils.
Strongyloides: worms that spread through contaminated soils.
Hookworms: worms with hooklike heads that attach to the intestines and spread through contaminated soil.
Whipworms: worms with a whiplike shape that spread via contaminated soil.
How Are Parasites Transmitted Through Food?
Parasites spread by laying eggs, feces, and contaminated food or water. Risk factors for parasite transmission through foods include:
Lack of proper hand washing before preparing or eating foods
The risk of intestinal parasites increases in humid and warm climates, such as subtropical and tropical areas (Asia, Latin America, sub-Saharan Africa, and the Caribbean) and in rural areas in Appalachia and the Southeastern United States.
Warm and humid climates, especially tropical and subtropical areas, including sub-Saharan Africa, Asia, Latin America, and the Caribbean (Strongyloides is more common in rural areas in the Southeastern U.S. and Appalachia
Reducing the risk of parasitic infections from food includes frequent hand washing, wearing gloves when preparing food, and thoroughly cooking foods — particularly meats.
Which Foods Carry a Risk of Parasitic Infection?
Foods that carry a higher risk of parasitic infection include:
Raw or Undercooked Meat
Not thoroughly cooking meats is a risk factor for parasitic infections through foods. Examples of specific parasites linked to raw or undercooked meat (beef, wild game, pork, or lamb) include:
Trichinella
Taenia
Toxoplasma
Giardia
Thoroughly cooking meat can kill parasites and prevent an infection.
Raw or Undercooked Fish and Seafood
Consuming raw or undercooked seafood is also a risk factor for foodborne illness and intestinal parasites. Examples of high-risk foods include sashimi, sushi, ceviche, and similar dishes.
Use caution when consuming undercooked fish and seafood, or simply cook these foods before eating them.
Unwashed Fruits and Vegetables
Fruits and vegetables can carry parasites if exposed to contaminated soil or water and remain raw or unwashed. Cook fresh produce or thoroughly wash fresh fruits and vegetables.
Intestinal parasites that can affect dairy cattle include:
Tapeworms
Flukes
Roundworms
Consuming unpasteurized milk, cheese, and other dairy foods can be risky. Always choose pasteurized products when consuming dairy foods. Check the food label to be sure.
Other High-Risk Foods
Other high-risk foods are those potentially exposed to contaminated water or prepared in unsanitary conditions. Examples of such higher-risk foods include:
Tips for reducing the risk of parasitic infections include purchasing pasteurized juices and milk and thoroughly washing fresh produce before consumption.
Lab Testing for Parasitic Infections
Lab testing for parasitic infections allows providers to properly diagnose a patient's condition and determine the most effective treatment plan.
Stool tests can diagnose parasites, particularly helminths and protozoa, that live in the intestines. Some of these tests require three or more stool samples during the course of several days. They detect parasites or their eggs.
Parasitic blood tests, such as serology are used to screen for antibodies in the blood. A blood smear showing parasites can be viewed under a microscope.
Colonoscopies and enteroscopies use long, flexible tubes with an attached camera to view the inside of the digestive tract and look for signs of intestinal parasites.
Imaging Procedures
X-rays, an MRI, a CT scan, or other imaging procedures can detect intestinal damage caused by parasites.
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When is Lab Testing Necessary?
Situations that warrant lab testing include patients with persistent symptoms, those with weakened immune systems, and individuals with high-risk exposures. Examples of symptoms of parasitic infections include:
Lab testing in public health and food safety settings is important to prevent the spread of parasites and communicable diseases.
How to Prevent Parasitic Infections from Food
There are several ways to reduce the risk of parasitic infections from food.
Always Use Safe Food Handling Practices
Safe food handling practices lessen the chance of intestinal parasites and other foodborne illnesses. Cook foods, particularly meats, chicken, fish, and seafood, to safe temperatures of:
Ground poultry: 165 °F
Leftovers: 165 °F
Casseroles: 165 °F
Poultry: 165 °F
Eggs: 160 °F
Ground meats: 160 °F
Pork, beef, lamb, veal, chops, and roasts: 145 °F
Ham: 145 °F
Fish: 145 °F
Shellfish: 145 °F
Use a meat thermometer to measure the internal temperature of the center of meat, poultry, fish, or seafood. Thoroughly wash all produce and choose pasteurized milk, milk products, and juices.
Food safety recommendations, particularly in commercial food service settings, include frequent handwashing, wearing gloves, and sanitizing dishes after each use. Commercial kitchen areas should be kept clean.
Ensure Consumer Awareness and Education
Educating the public about the risk of foodborne parasites, including symptoms to watch for, ways to cook food properly, and when to get tested for intestinal parasites, is important. Many people do not realize they have intestinal parasites, and practitioners might not know to test for them, without increased awareness.
Take Public Health Measures
Public health measures include following food safety and sanitation regulations and scheduling routine inspections to reduce foodborne parasites. Collaboration between healthcare professionals and public health agencies is crucial for preventing and prompt identification of foodborne contamination.
[signup]
Key Takeaways
The following food safety tips reduce the risk of a parasitic infection:
Foods to avoid with parasites include raw or undercooked meats, poultry, fish, seafood, and eggs.
Don’t eat unwashed fruits and vegetables.
Avoid unpasteurized milk and juices.
Cook all meats to the recommended internal temperatures to kill any parasites.
Follow safe food handling practices.
Consider lab testing for early detection of intestinal parasites and seek medical advice at the first sign of a parasitic infection.
Foodborne parasitic infections are common, affecting at least 12 million people in the United States and more than 2 billion people worldwide. However, such infections often go undiagnosed due to poor awareness of these common microorganisms.
Foodborne parasitic infections often stem from protozoa or intestinal worms getting inside the digestive tract via contaminated water, food, or exposure to feces. It’s vital to practice good hygiene, adopt food safety strategies, and know which foods to avoid with parasites.
[signup]
Common Types of Parasites in Food
Parasites need a host to survive, grow, and spread. About 25% of the population worldwide has a parasite-related infection. The most common types of parasites found in foods are:
Protozoa
Protozoa are microscopic, one-celled organisms that can live in the intestines. Protozoa spread via contaminated water or food, insect bites, and person-to-person contact. Tens of thousands of types of protozoans exist, including:
Ciliates: ciliates, including B. coli, contain short, hairlike structures that allow these parasites to gather food and move.
Amoeba: amoebas, including E. histolytica, use false feet used to move.
Sporozoans: sporozoans, such as cryptosporidium and plasmodium, don’t move on their own but eat the digested food or body fluids of their host.
Flagellates: flagellates, including giardia and toxoplasma, use whip-like structures to move and explore their surroundings.
Helminths
Helminths are parasitic worms that can live in the gastrointestinal (GI) tract, including the stomach and small and large intestines. Parasitic worms may be visible to the naked eye.
Examples include:
Tapeworms: flat, long worms that live in the intestines and feed off nutrients in their host’s food. The eggs they lay spread through infected water or foods like undercooked fish, beef, and pork.
Flukes: flatworms that spread via aquatic animals (crabs, fish, snails, etc.), aquatic plants, and contaminated water.
Roundworms: parasites that live in the intestines and spread via foods (particularly pork), infected soil, and feces.
Pinworms: threadlike worms that spread through eggs in feces.
Ascaris: worms that resemble tiny earthworms and spread via contaminated soils and produce grown in these soils.
Strongyloides: worms that spread through contaminated soils.
Hookworms: worms with hooklike heads that attach to the intestines and spread through contaminated soil.
Whipworms: worms with a whiplike shape that spread via contaminated soil.
How Are Parasites Transmitted Through Food?
Parasites spread by laying eggs, feces, and contaminated food or water. Risk factors for parasite transmission through foods include:
Lack of proper hand washing before preparing or eating foods
The risk of intestinal parasites increases in humid and warm climates, such as subtropical and tropical areas (Asia, Latin America, sub-Saharan Africa, and the Caribbean) and in rural areas in Appalachia and the Southeastern United States.
Warm and humid climates, especially tropical and subtropical areas, including sub-Saharan Africa, Asia, Latin America, and the Caribbean (Strongyloides is more common in rural areas in the Southeastern U.S. and Appalachia
Reducing the risk of parasitic infections from food includes frequent hand washing, wearing gloves when preparing food, and thoroughly cooking foods — particularly meats.
Which Foods Carry a Risk of Parasitic Infection?
Foods that carry a higher risk of parasitic infection include:
Raw or Undercooked Meat
Not thoroughly cooking meats is a risk factor for parasitic infections through foods. Examples of specific parasites linked to raw or undercooked meat (beef, wild game, pork, or lamb) include:
Trichinella
Taenia
Toxoplasma
Giardia
Thoroughly cooking meat can help manage the risk of parasites and support the prevention of an infection.
Raw or Undercooked Fish and Seafood
Consuming raw or undercooked seafood is also a risk factor for foodborne illness and intestinal parasites. Examples of high-risk foods include sashimi, sushi, ceviche, and similar dishes.
Use caution when consuming undercooked fish and seafood, or simply cook these foods before eating them.
Unwashed Fruits and Vegetables
Fruits and vegetables can carry parasites if exposed to contaminated soil or water and remain raw or unwashed. Cook fresh produce or thoroughly wash fresh fruits and vegetables.
Intestinal parasites that can affect dairy cattle include:
Tapeworms
Flukes
Roundworms
Consuming unpasteurized milk, cheese, and other dairy foods can be risky. Always choose pasteurized products when consuming dairy foods. Check the food label to be sure.
Other High-Risk Foods
Other high-risk foods are those potentially exposed to contaminated water or prepared in unsanitary conditions. Examples of such higher-risk foods include:
Tips for reducing the risk of parasitic infections include purchasing pasteurized juices and milk and thoroughly washing fresh produce before consumption.
Lab Testing for Parasitic Infections
Lab testing for parasitic infections allows providers to properly diagnose a patient's condition and determine the most effective treatment plan.
Stool tests can help identify parasites, particularly helminths and protozoa, that live in the intestines. Some of these tests require three or more stool samples during the course of several days. They detect parasites or their eggs.
Parasitic blood tests, such as serology, are used to screen for antibodies in the blood. A blood smear showing parasites can be viewed under a microscope.
Colonoscopies and enteroscopies use long, flexible tubes with an attached camera to view the inside of the digestive tract and look for signs of intestinal parasites.
Imaging Procedures
X-rays, an MRI, a CT scan, or other imaging procedures can detect intestinal damage that may be caused by parasites.
[signup]
When is Lab Testing Necessary?
Situations that may warrant lab testing include patients with persistent symptoms, those with weakened immune systems, and individuals with high-risk exposures. Examples of symptoms of parasitic infections include:
Lab testing in public health and food safety settings is important to help prevent the spread of parasites and communicable diseases.
How to Prevent Parasitic Infections from Food
There are several ways to reduce the risk of parasitic infections from food.
Always Use Safe Food Handling Practices
Safe food handling practices can help lessen the chance of intestinal parasites and other foodborne illnesses. Cook foods, particularly meats, chicken, fish, and seafood, to safe temperatures of:
Ground poultry: 165 °F
Leftovers: 165 °F
Casseroles: 165 °F
Poultry: 165 °F
Eggs: 160 °F
Ground meats: 160 °F
Pork, beef, lamb, veal, chops, and roasts: 145 °F
Ham: 145 °F
Fish: 145 °F
Shellfish: 145 °F
Use a meat thermometer to measure the internal temperature of the center of meat, poultry, fish, or seafood. Thoroughly wash all produce and choose pasteurized milk, milk products, and juices.
Food safety recommendations, particularly in commercial food service settings, include frequent handwashing, wearing gloves, and sanitizing dishes after each use. Commercial kitchen areas should be kept clean.
Ensure Consumer Awareness and Education
Educating the public about the risk of foodborne parasites, including symptoms to watch for, ways to cook food properly, and when to get tested for intestinal parasites, is important. Many people do not realize they have intestinal parasites, and practitioners might not know to test for them, without increased awareness.
Take Public Health Measures
Public health measures include following food safety and sanitation regulations and scheduling routine inspections to reduce foodborne parasites. Collaboration between healthcare professionals and public health agencies is crucial for preventing and prompt identification of foodborne contamination.
[signup]
Key Takeaways
The following food safety tips can help reduce the risk of a parasitic infection:
Foods to avoid with parasites include raw or undercooked meats, poultry, fish, seafood, and eggs.
Don’t eat unwashed fruits and vegetables.
Avoid unpasteurized milk and juices.
Cook all meats to the recommended internal temperatures to help manage the risk of parasites.
Follow safe food handling practices.
Consider lab testing for early detection of intestinal parasites and seek medical advice at the first sign of a parasitic infection.
The information in this article is designed for educational purposes only and is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose or treat any health problems or illnesses without consulting a doctor. Consult with a health care practitioner before relying on any information in this article or on this website.
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Lab Tests in This Article
GI Effects® Comprehensive Profile - 3 day by Genova Diagnostics
Stool
The GI Effects® Comprehensive Profile is a group of advanced stool tests that assess digestive function, intestinal inflammation, and the intestinal microbiome to assist in the management of gastrointestinal health. This is the 3-day version of the test; it is also available as a 1-day test.
Comprehensive Stool Analysis + Parasitology - 3 Day by Doctor's Data
Stool
The CSAP profile helps pinpoint the causes of gastrointestinal symptoms and chronic systemic conditions, and measures key markers of digestion, absorption and inflammation. It includes comprehensive bacteriology and yeast cultures, detection of infectious pathogens and parasites, and antimicrobial susceptibility testing to prescriptive and natural agents. This is a 3-DAY SAMPLE COLLECTION.
Comprehensive Stool Analysis by Access Med Labs
Stool
This test is used to detect pathogens in the stool.
Comprehensive Stool Analysis by Mosaic Diagnostics (formerly Great Plains)
Stool
The Comprehensive Stool Analysis detects pathogenic microorganisms and evaluates beneficial bacteria levels, intestinal immune function, overall intestinal health, and inflammation markers. It also provides helpful information about prescription and natural products effective against specific strains detected in the sample.
Blood Parasite Smear by Access Med Labs
Whole Blood
This test identifies malarial parasites to help determine treatment and prognosis.
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