Food Poisoning - Symptoms

How serious the symptoms of food poisoning are depends on many factors. These factors include the kind of bacteria, the amount consumed, and the individual's general health and sensitivity to the bacterial toxin.

(Source: Food Safety and Inspection Service, U.S. Department of Agriculture. Reproduced by permission of Stanley Publishing.)
(Source: Food Safety and Inspection Service, U.S. Department of Agriculture. Reproduced by permission of
Stanley Publishing

Pathogen Common Host(s)
(Source: Food Safety and Inspection Service, U.S. Department of Agriculture. Reproduced by permission of Stanley Publishing.)
Campylobacter Poultry
E.coli 0157:H7 Undercooked, contaminated ground beef
Listeria Found in a variety of raw foods, such as uncooked meats and vegetables, and in processed foods that become contaminated after processing
Salmonella Poultry, eggs, meat, and milk
Shigella This bacteria is transmitted through direct contact with an infected person or from food or water that become contaminated by an infected person
Vibrio Contaminated seafood


Symptoms of Salmonella poisoning appear twelve to seventy-two hours after a person has eaten contaminated food. These symptoms are the traditional food poisoning symptoms, such as abdominal pain, diarrhea, vomiting, and fever. The symptoms usually last two to five days. In the most severe cases, dehydration can be a serious problem. People usually recover without being treated with antibiotics. However, they usually continue to feel tired for a week after the symptoms have passed.

Staphylococcus aureus

Symptoms of Staphylococcus aureus poisoning usually appear quickly, often within eight hours of eating the contaminated food. The most serious symptoms are vomiting, diarrhea, and severe abdominal cramps. These symptoms usually last three to six hours, and rarely more than twenty-four hours. Most people recover without medical assistance. Deaths are rare.

Escherichia coli (E. coli)

Symptoms of E. coli poisoning appear more slowly than symptoms of other kinds of food poisoning. These symptoms normally first arise one to three days after eating contaminated food. One symptom is severe abdominal cramps. Another symptom is diarrhea that is watery at first, but then becomes bloody. Both fever and vomiting are likely to be absent with E. coli poisoning. In most cases, the watery, bloody diarrhea disappears after one to eight days.

A possible complication of E. coli infection, especially in children under five and elderly people, is hemolytic uremic syndrome (HUS). This disease causes the kidneys to fail and red blood cells to be destroyed. Most people recover fully from HUS, but the disease can be fatal.

Campylobacter jejuni (C. jejuni)

The first symptoms of C. jejuni poisoning appear two to five days after eating contaminated food. These symptoms include fever, abdominal pain, nausea, headache, muscle pain, and diarrhea. The diarrhea can be watery or sticky. It may also contain blood. Symptoms of the infection last from seven to ten days. Relapses (reoccurrences of the infection) occur in about onequarter of all patients. Dehydration can be a serious complication.


Symptoms of Shigella poisoning appear thirty-six to seventy-two hours after eating contaminated food. These symptoms are slightly different from other forms of food poisoning. The usual watery diarrhea, nausea, vomiting, abdominal cramps, and fever are present. But up to 40 percent of children infected with the bacterium show neurological (nervous system) problems. These symptoms include seizures, confusion, headache, lethargy (listlessness), and a stiff neck.

The disease usually lasts two to three days. Dehydration is a common complication. Most people recover on their own. But they may feel exhausted for days or weeks after symptoms have disappeared. Children who are malnourished (poorly fed) or who have weakened immune systems can die of the infection.

Clostridium botulinum (C. botulinum)

Symptoms of adult botulism usually appear eighteen to thirty-six hours after the contaminated food is eaten. The first signs of botulism are a feeling of weakness and dizziness, followed by double vision. As the bacteria spread through the nervous system, paralysis begins. The patient finds it difficult to speak and swallow. Eventually, the muscles of the respiratory (breathing) system are affected. The patient may die of asphyxiation (suffocation; pronounced as-FIK-see-A-shun). People who show the symptoms of botulism require immediate medical attention.

Infant botulism was first recognized in 1976. It differs from adult botulism in both causes and symptoms. Infant botulism occurs when a child under the age of one year inhales or swallows the spores of C. botulinum. Spores are reproductive cells from non-flowering plants, such as mosses and ferns. C. botulinum spores are found in the soil. A more common source in the case of food poisoning, however, is honey.

Once inside an infant's body, C. botulinum spores become stuck in the baby's intestines. They begin to grow and release their neurotoxin. Symptoms begin to appear very gradually. Initially, the baby is constipated. Eventually, it loses interest in eating, begins to drool, becomes weak and lethargic, and makes a very distinctive crying sound. Eventually the baby loses its ability to control its head muscles. Beyond that point, paralysis sets in throughout the baby's body.

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