Digestive Diseases: Food Poisoning

Last Editorial Review: 11/18/2010

Food poisoning is a common, yet distressing and sometimes life-threatening problem for millions of people in the U.S., and throughout the world. People infected with foodborne organisms may be symptom-free or may have symptoms ranging from mild intestinal discomfort to severe dehydration and bloody diarrhea. Depending on the type of infection, people can even die as a result of food poisoning.

More than 250 different diseases can cause food poisoning. Some of the most common diseases are infections caused by bacteria, such as Campylobacter, Salmonella, Shigella, E. coli O157:H7, Listeria, and botulism.

What Is Campylobacter Infection?

Campylobacter is a bacterium that causes acute diarrhea. Transmission usually occurs through ingestion of contaminated food, water, or unpasteurized milk, or through contact with infected infants, pets or wild animals.

Is Campylobacter Infection a Serious Health Concern?

It can be, especially in those with weakened immune systems. In rare cases, Campylobacter infection can cause additional problems such as arthritis or brain and nerve problems. Occasionally, these problems occur after the diarrhea has stopped.

How Is Campylobacter Infection Diagnosed and Treated?

If you think you may have been exposed to the infection, see your doctor. By testing a sample of your stool, the bacteria can be identified.

If you are found to have the infection, you will likely recover on your own without treatment within 2-5 days. Drink plenty of fluids to prevent becoming dehydrated.

In more severe cases, antibiotics (such as Cipro), if given early in the illness, can be used to shorten the length of time you are sick.

What Is Salmonella?

Salmonella is a bacterial infection that can be passed on to humans from domestic and wild animals, including poultry, pigs, cattle, and pets. But most often, it is caused by drinking unpasteurized milk or by eating undercooked poultry and poultry products such as eggs. Any food prepared on surfaces contaminated by raw chicken or turkey can also become tainted with salmonella. Less often, the illness may stem from food contaminated by a food worker.

Salmonella can escape from the intestine and go into the blood and travel to other organs. It may become a chronic infection in some people, who can be symptom-free yet capable of spreading the disease to others.

Salmonella infections occur worldwide, but it is most extensively reported in North America and Europe.

Symptoms include acute onset of:

These symptoms, along with loss of appetite, can persist for several days.

Can Salmonella Infection Cause Serious Health Problems?

Although most people recover completely (which sometimes can take several months), salmonella infection may cause a condition known as Reiter's syndrome in a small percentage of people. Symptoms of Reiter's syndrome include joint pain, eye irritation and pain when urinating. The joint pain of Reiter's syndrome may develop into a chronic arthritis.

Salmonella infection rarely causes death, although it can occur in the very young, very old or among those who have compromised immune systems.

How Is Salmonella Infection Diagnosed and Treated?

If you think you may have been exposed to the infection, see your doctor. By testing a sample of your stool, the bacteria can be identified.

Salmonella infections usually go away in 5-7 days and often do not require treatment unless you become severely dehydrated or the infection spreads outside of the intestines. If treatment is needed, antibiotics are prescribed.

How Can I Prevent Getting Salmonella?

To prevent salmonella infection, avoid eating raw or undercooked meat or poultry products, including eggs. It is also important to avoid "cross-contamination" which can occur if food is being prepared using the same utensils, or on the same surfaces, as those used for raw or undercooked meats or poultry products.

Wash your hands frequently during and after food preparation. Those with a salmonella infection should not be involved in food preparation.

Wash your hands with soap after handling reptiles, birds, or after contact with pet feces. Avoid contact between reptiles (turtles, iguanas, other lizards, and snakes) and infants or people with weakened immune systems.


According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

What Is Shigella?

Shigella is a bacteria generally transmitted through feces. It causes dysentery, an infection of the intestines causing severe diarrhea. The disease generally occurs in tropical or temperate climates, especially under conditions of crowding, where personal hygiene is poor.

Symptoms include:

How Is Shigella Diagnosed and Treated?

If you think you may have been exposed to shigella, see your doctor. By testing a sample of your stool, the bacteria can be identified.

People with mild infections usually recover within a few days without special treatment. Drinking fluids to prevent dehydration is usually all that is needed. However, with severe infections, antibiotics and more aggressive treatment to prevent dehydration are often needed.

How Can Shigella Infection Be Prevented?

The shigella bacteria from stools of infected people can be passed to others if hygiene or hand-washing habits are inadequate. To help prevent transmitting the infection, you should always wash your hands thoroughly after using the bathroom or changing diapers.

What Is E. Coli?

E. coli O157:H7 is a growing cause of foodborne illness. An estimated 73,000 cases of these E. coli infections occur in the U.S. every year, according to the CDC.

Most E. coli O157:H7 infections have been associated with eating undercooked, contaminated ground beef. Drinking unpasteurized milk and swimming in or drinking sewage-contaminated water can also cause infection. Bacteria from stools of infected people can be passed to others if less than adequate hygiene or hand-washing habits are present. Young children often continue to shed the organism in their feces for a week or two after their illness resolves.

Symptoms can include severe bloody diarrhea and abdominal cramps, but sometimes the infection causes non-bloody diarrhea, a slight fever, or no symptoms at all.

Can E. Coli Infection Cause Serious Health Problems?

Yes. In some people, particularly children under the age of 5 and the elderly, the infection can cause a serious complication called hemolytic uremic syndrome. Hemolytic uremic syndrome causes the destruction of red blood cells and kidney failure. About 2%-7% of infections lead to this complication, according to the CDC.

How Is E. Coli Infection Diagnosed and Treated?

If you think you may have been exposed to the infection, see your doctor. By testing a sample of your stool, the bacteria can be identified. It is recommended by the CDC that all those who have sudden, bloody diarrhea get their stool tested for this type of E. coli.

Most people recover on their own within about 5-10 days.

Hemolytic uremic syndrome is a medical emergency and most often will be treated in an intensive care unit.

How Is E. Coli Infection Prevented?

You can prevent E. coli infection by thoroughly cooking ground beef, avoiding unpasteurized milk, and washing your hands carefully after handling meat, using the bathroom or changing diapers.

What Is Listeria Infection?

Listeria is a bacteria primarily found in soil and water. According to the CDC, vegetables can become contaminated from soil or from manure used as fertilizer. Animals carrying the bacterium can also contaminate food. Listeria has been found in many types of uncooked foods, such as meats and vegetables, as well as in processed foods that become contaminated after processing, such as soft cheeses (such as feta and crumbled blue cheese) and cold cuts.

Unpasteurized milk or foods made from unpasteurized milk may also be sources of listeria infection. Listeria is killed by pasteurization, and heating procedures used to prepare ready-to-eat processed meats should be sufficient to kill the bacterium. However, unless good manufacturing practices are followed, contamination can occur even after processing.

According to the CDC, an estimated 2,500 people in the U.S. become seriously ill from a listeria infection each year, and of these 500 will die. The CDC reports that those at increased risk for developing listeriosis include:

Symptoms can include:

  • Fever
  • Muscle aches
  • Nausea
  • Diarrhea

If infection spreads to the nervous system (brain and spinal cord), the following symptoms can occur:

Infected pregnant women may experience only a mild, flu-like illness; however, infection during pregnancy can lead to premature delivery, infection of the newborn or even stillbirth. There is no routine screening test to find out if you are likely to contract listeria infection during pregnancy. If you have symptoms of listeriosis, consult your doctor immediately.

How Is Listeria Infection Diagnosed and Treated?

Listeria infection is often diagnosed by medical history and confirmed by blood or spinal fluid tests.

Antibiotic treatment will usually cure the infection, and when given promptly to an infected pregnant woman, may prevent infection of her fetus.

Even with prompt treatment, some infections result in death. In the elderly and people with other serious medical problems, these infections are more likely to be fatal.

What Is Botulism?

The bacterium Clostridium botulinum is responsible for causing the rare but serious illness botulism.

According to the CDC, the three main types of botulism are foodborne, wound, and infant botulism. Foodborne botulism is caused by eating foods that contain the botulism toxin. Wound botulism, which is very rare, is caused by a toxin produced from a wound infected with C. botulinum. Infant botulism is caused by consuming the spores of botulinum bacteria, which grow in a child's intestines.

All forms of botulism can be deadly and are considered medical emergencies.

Symptoms include:

In infants with botulism the symptoms include:

If these symptoms are untreated, they may lead to paralysis of the arms, legs, trunk, and respiratory muscles. Symptoms of foodborne botulism usually develop 18 to 36 hours after consuming contaminated food, but symptoms can occur as early as six hours or as late as a week to 10 days.

How Is Botulism Diagnosed and Treated?

Diagnosis is made by the presence of appropriate symptoms of nerve weakness and by laboratory tests that detect the toxin or by culture of C. botulinum from the person's stool.

The respiratory failure (inability to breathe) and paralysis that occur with severe botulism may require intensive medical and nursing care in a hospital.

If diagnosed in its early stages, foodborne botulism can be treated with an antitoxin medication.

Your doctor may also try to remove any contaminated food left in the digestive system by inducing vomiting or by using enemas.

Infants infected with the bacteria require hospitalization and possibly care in an intensive care unit. The botulism antitoxin is not recommended for infants.

How Can Botulism Be Prevented?

Although there are very few cases of botulism poisoning each year, prevention is extremely important. According to the CDC, foodborne botulism has often been linked to home-canned foods with a low acid content. These foods include asparagus, green beans, beets, and corn. People have also become infected from other sources including chopped garlic in oil, chili peppers, tomatoes, improperly handled baked potatoes cooked in aluminum foil, and home-canned or fermented fish (such as sardines).

Persons who can their own food should follow strict canning procedures to reduce contamination of foods.

Honey should not be given to children younger than 12 months of age, as it can contain spores of C. botulinum and is known to cause infant botulism.

Reviewed by The Cleveland Clinic Department of Gastroenterology
SOURCE: The Centers for Disease Control and Prevention
Reviewed by Venkat Mohan, MD on September 13, 2008

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