What Causes Food Borne Illness?

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The following organisms are the most often implicated causes of food borne illness. The name of each organism is listed below with a link to further information. 

This organism causes two forms of illness: emetic and diarrheal. The onset of emetic disease is from one-half hour to 5 hours. The main symptoms are nausea and vomiting; diarrhea may occur. The diarrheal form has an onset of 8 to 16 hours. The main foods implicated are fried rice, boiled rice, cereal products, puddings, sauces, vegetables, and meatloaf.


Campylobacteriosis has an onset of 2 to 10 days (average is 3 to 5 days). The symptoms include bloody, foul-smelling diarrhea, fever, abdominal pain, nausea, headache, and muscle pain. The foods most commonly causing illness are raw or undercooked poultry, unpasteurized milk, raw or undercooked seafood, beef liver, and untreated water.


Onset is 9 to 15 hours with diarrhea, vomiting, nausea, and abdominal cramps. Meat products are a major cause if left out at room temperature for more than 2 hours (stews, gravies, meat pies, roasts, meat products, and poultry).


The onset of this organism is 3 to 4 days and the symptoms can be rather severe including bloody diarrhea, severe stomach cramps, nausea, and vomiting. This organism can cause HUS (hemolytic uremic syndrome) and lead to kidney failure and death. The most implicated food has been raw and undercooked hamburger meat. Other foods are unpasteurized milk, very rare roast beef, and unpasteurized apple juice.


Photo of a Consumer Microbiology Milk Analyst testing a Raw for Retail milk sample for aerobic bacteria.

This organism is found in the environment making it a prime bug to get into food in the processing plant. It has been found in raw and processed meat (hot dogs, luncheon meats), raw seafood, cole slaw, soft cheese, unpasteurized milk, and cheese made from unpasteurized milk. The onset can be from several days to 2 to 6 weeks. Symptoms include fever, chills, headache, vomiting, diarrhea, meningitis, and spontaneous abortion.


Salmonellosis is probably the best known illness from food. The average onset of symptoms is 12 to 36 hours although it can be as early as 6 hours or as long as 72 hours. The symptoms include stomach pain, diarrhea, watery stools, nausea, chills, fever, and headache—occasionally the diarrhea may be bloody. The following foods have caused Salmonellosis: raw or undercooked meats, poultry and eggs (the yolks), unpasteurized milk, fruits, vegetables, coconuts, yeast, smoked fish, dry milk, and chocolate candy.
Shigellosis, which is uncommon in developed countries, can be caused by cold mixed salads (potato, egg, macaroni, tuna, shrimp), meat, dairy products, vegetables, apple cider, contaminated water, and ice. Onset is 1 to 6 days and the symptoms are stomach cramps, vomiting, diarrhea, fever, and bloody diarrhea.

Foods such as cooked ham, poultry, salads, cream-filled pastries, meat products, potato salad, dressing, sauces and gravies, cheese, fish salad, and bread pudding have caused Staphylococcus aureus food poisoning. The onset is anywhere from 1 to 8 hours and the following symptoms are typical: stomach pain, nausea, vomiting, diarrhea, fever, chills, headaches, dizziness, and weakness.


The sudden onset of profuse watery diarrhea (often called rice-water stools) is typical of this illness with this organism, as are abdominal pain and rapid dehydration. The onset is 2 to 3 days and the foods implicated are raw mussels, shrimp, fish, cucumbers, mixed and moist foods, or foods washed with contaminated water.


This strain is does not cause as severe a disease as the O1 strain. The onset is the same and the symptoms are watery diarrhea, abdominal cramps, nausea, vomiting, and dehydration. Pickled herring and shellfish have been implicated.


Foods implicated with vibrio parahaemolyticus include warm-water shellfish (such as those from the Gulf of Mexico), raw fish, raw marine foods, saltwater fish, mollusks, crustaceans, fish products, cucumbers, and salty foods from cross-contamination. The onset of illness is 12 hours with symptoms ranging from mild to severe watery diarrhea with nausea and vomiting.


This species of Vibrio is the most dangerous, especially to compromised patients. The onset is anywhere from 1 hour to 1 week. The symptoms include chills, fever, and skin lesions (from open skin in the marine environment). The disease may progress to septicemia which may be fatal in 6 hours. Septicemia is fatal in 50 percent of cases.


Yersiniosis is not common but it does mimic appendicitis, which leads to unnecessary appendectomies. It also causes acute abdominal pain, fever, headache, and diarrhea. Onset is form 24 to 36 hours, or longer. Typically associated is unpasteurized milk, dry milk, soil, water, and animals (pigs).


Other Foodborne Illness Sites: CDCFDAUSDA - Foodsafety


Note: External links to other sites are intended to be informational and do not have the endorsement of the Texas Department of State Health Services. These sites may also not be accessible to people with disabilities.