☆ Foodborne Illnesses and Pathogens

Foodborne Illnesses and Pathogens 

Foodborne illness is a sickness caused by consuming pathogenic microorganisms or toxins inside contaminated foods. Most cases of foodborne illness typically go undiagnosed because the symptoms are not severe enough that an ill person would not seek medical care. However, some foodborne illnesses can lead to food allergies, chronic complications, blood poisoning, and even death. 

People who are usually at risk of foodborne illnesses are infants, young children, immunocompromised people, pregnant women, and the elderly.

Most microbial pathogens, like bacteria and viruses, contaminate food by being in contact with infected animals or humans. The most well-known routes include cross-contamination, contamination by feces, and contamination by an infected individual. 

Please note: most estimated infections per year are in the United States alone.

Bacteria

Salmonella species

Food Sources: eggs, raw meat, undercooked meat, poultry, fish, raw sprouts, peanut butter, and unpasteurized milk.

Symptoms: diarrhea, abdominal cramping, fevers, nausea, vomiting, and headaches.

Estimated infections per year: 1.35 million cases.

Additional info: Around 20% of the cases are from eating undercooked eggs or egg dishes.

Campylobacter jejuni

Food Sources: raw meat, undercooked meat, raw poultry, undercooked poultry, unpasteurized milk, cheese, and contaminated water.

Symptoms: muscle pain, abdominal cramping, diarrhea, and fever.

Estimated infections per year: 1.5 million cases.

Additional info: Can cause Guillain-Barre syndrome. GBS causes the peripheral nerves to be damaged by the body's own immune system.

E. coli

Food Sources: undercooked ground beef, lettuce, spinach, sprouts, unpasteurized milk, unpasteurized juice, and cheeses.

Symptoms: abdominal cramping, diarrhea, hemolytic uremic syndrome, fever, and vomiting.

Estimated infections per year: 48 million cases.

Additional info: petting zoos, lakes, and swimming pools can contain E. coli.

Shigella species

Food Sources: water supplies, foods contaminated by infected food handlers with bad hygiene.

Symptoms: abdominal cramping, diarrhea, and fever.

Estimated infections per year: 450,000 cases.

Additional info: it is common in day-care centers for poor hygiene.

Staphylococcus aureus

Food Sources: ham, chicken, tuna, egg, cream-filled pastries, custards, and whipped cream.

Symptoms: nausea, vomiting, abdominal cramping, and diarrhea.

Estimated infections per year: 241,000 cases.

Additional info: staph is a bacteria on the skin and in the nose. Staph does not cause illness in healthy people who carry it, but the bacteria can make toxins in food.

Clostridium perfringens

Food Sources: beef, poultry, and gravy.

Symptoms: diarrhea, vomiting, fever, and signs of dehydration.

Estimated infections per year: 1 million cases.

Additional info: multiplies rapidly in prepared foods held for an extended time at room temperature.

Listeria monocytogenes

Food Sources: unpasteurized milk, ice cream, soft cheeses, raw meats, raw vegetables, and ready-to-eat deli meats.

Symptoms: fever, muscle aches, nausea, vomiting, and diarrhea. 

Estimated infections per year: 1,600 cases.

Additional info: Can cause Listeriosis. Listeriosis spreads to the nervous system causing: severe headaches, stiff neck, confusion, loss of balance, convulsions, miscarriages for pregnant women, and death.

Clostridium botulinum

Food Sources: honey, incorrectly home-canned vegetables. meats, fish, and bottled garlic.

Symptoms: difficulty swallowing, muscle weakness, double vision, drooping eyelids, blurry vision, slurred speech, difficulty breathing, difficulty moving the eyes, vomiting, nausea, abdominal cramping, and diarrhea.

Estimated infections per year: 110 cases.

Additional info: honey should not be given to infants younger than 1 year of age because it can have botulism spores.

Vibrio

V. parahaemolyticus

Food Sources: raw shellfish, and undercooked shellfish.

Symptoms: diarrhea, vomiting, fever, and chills.

Estimated infections per year: 30-40 cases.

V. vulnificus

Food Sources: raw shellfish, and undercooked shellfish.

Symptoms: vomiting, diarrhea, abdominal cramping, bloodstream infection with fever, chills, decreased blood pressure, and blistering skin lesions.

Estimated infections per year: 150-200 cases.

V. cholerae

Food Sources: contaminated water and food, human carriers.

Symptoms: dehydrating diarrhea, vomiting, dehydration, cardiovascular collapse, and death.

Estimated infections per year: 1.3-4 million cases.

Viruses

Norovirus

Food Sources: shellfish from contaminated waters, foods prepared by infected handlers, vegetables, and fruits.

Symptoms: "stomach flu" or "stomach bug"- severe diarrhea, nausea, vomiting, fever, headaches, and body aches.

Estimated infections per year: 19-21 million cases

Hepatitis A virus

Food Sources: foods prepared by infected handlers, sandwiches, pastries, salads, shellfish from contaminated waters, vegetables, and fruits.

Symptoms: fatigue, nausea, vomiting, abdominal pain, jaundice, may cause liver damage, and death.

Estimated infections per year: 1,200-1,800 cases.

Parasites

Trichinella spiralis

Food Sources: pork, and wild game.

Symptoms: muscle weakness, fluid retention in the face, flu-like symptoms, and fever. Larvae can live in muscles for years.

Estimated infections per year: 10,000 cases.

Additional info: cooking pork to 145F (63C) plus 3 minutes of rest before carving will kill Trichinella. Freezing it for 3 days at -4F (-20C).

Anisakis

Food Sources: raw and undercooked fish.

Symptoms: violent stomach pain, and vomiting when worms burrow into the stomach or intestine wall.

Tapeworms

Food Sources:  raw beef, undercooked beef, pork, and fish from poor sanitary facilities.

Symptoms: abdominal discomfort, diarrhea, and general malaise.

Estimated infections per year: 1,000 cases.

Additional info: common worldwide, rare in the U.S.

Toxoplasma gondii

Food Sources: raw or undercooked seafood, pork, beef, lamb, and venison. Unwashed fruits and vegetables.

Symptoms: fever, headache, sore muscles, diarrhea. It can spread to the brain, eyes, heart, or other muscles. It can be fatal to the fetus of pregnant women.

Estimated infections per year: 86,700 cases.

Additional info: The parasite is spread to humans from animals, including cats, the main reservoir of the disease.

Cryptosporidium

Food Sources: water, any food contaminated by a food handler or environmental source.

Symptoms: abdominal pain, diarrhea, fever, nausea, vomiting, and weight loss. Those with impaired immune systems become more ill.

Estimated infections per year: 823,000 cases.

Additional info: one of the most common waterborne diseases worldwide. It can be spread in water parks, lakes, and rivers.

Mycotoxins

Aflatoxin

Food Sources: corn, peanuts, rice, spices, and nuts.

Symptoms: liver damage or failure, malnutrition, malaise, impaired immune function.

Additional info: aflatoxin b-1 is the most common fungal toxin contaminating grains and nuts.

Ergot

Food Sources: inappropriately stored grains, rye.

Symptoms: hallucinations, severely constricted blood flow to limbs, involuntary muscle twitching, contractions, tingling, and burning sensations.

Additional info: common throughout history but rare today due to inspections and agricultural practices.

Fish and Shellfish Toxins

Shellfish poisoning

Food Sources: mussels, clams, scallops, oysters, crabs, and lobster.

Symptoms: paralytic onset: numb and tingling skin, respiratory paralysis, and death. Diarrheic onset: nausea, vomiting, diarrhea, abdominal pain, chills, headache, and fever. Neurotoxic onset: tingling and numbness of the mouth and throat, muscle aches, dizziness, reversal of sensations of hot and cold, diarrhea, and vomiting. Amnesic onset: vomiting, diarrhea, abdominal pain, confusion, memory loss, disorientation, seizure, coma, and death.

Additional info: not inactivated by cooking for freezing.

Tetrodotoxin

Food Sources: pufferfish (fugu) liver, intestines, and skin.

Symptoms: mouth numbness, headache, nausea, diarrhea, vomiting, paralysis, and respiratory distress.

Additional info: fugu is a delicacy in Japan, where chefs must be licensed to prepare and serve this fish.

Plant Toxins

Safrole

Food Sources: sassafras, mace, and nutmeg.

Symptoms: cancer when consumed in high doses.

Additional info: once used as a food additive but it is now banned.

Solanine

Food Sources: potato sprouts, and green spots on potato skins.

Symptoms: nausea, diarrhea, vomiting, hallucinations, loss of sensation, and paralysis.

Additional info: can be prevented by storing potatoes in a dark area and discarding sprouts, and bruised or green-tinged spots.

Mushroom toxins

Food Sources: several mushroom species, such as amanita.

Symptoms: stomach upset, dizziness, hallucinations, liver damage, kidney damage, coma, and death.

Additional info: illness is almost always caused by wild mushrooms picked by non-experts.

Herbal teas

Food Sources: teas containing senna or comfrey.

Symptoms: abdominal pain, nausea, vomiting, and liver damage.

Thank you for reading!