Topic Overview

What is salmonellosis?

Salmonellosis is a type of food poisoning caused by the Salmonella bacterium. There are many different kinds of these bacteria. Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common types in the United States.

Every year approximately 40,000 cases of salmonellosis are reported in the U.S. Many milder cases are not diagnosed or reported, so the actual number of infections may be 30 or more times greater.¹ Salmonellosis is more common in the summer than in the winter. Children are the most likely to get salmonellosis. Young children, older adults, and people who have impaired immune systems are the most likely to have severe infections.

What causes salmonellosis?

You can get salmonellosis by eating food contaminated with salmonella. This can happen in the following ways:

• Food may be contaminated during food processing or food handling.
• Food may become contaminated by the unwashed hands of an infected food handler. A frequent cause is a food handler who does not wash his or her hands with soap after using the bathroom.
• Salmonella may also be found in the feces of some pets, especially those with diarrhea. You can become infected if you do not wash your hands after contact with these feces.
• Reptiles, baby chicks and ducklings, and small rodents such as hamsters are particularly likely to carry Salmonella. You should always wash your hands immediately after handling one of these animals, even if the animal is healthy. Adults should also be careful that children wash their hands after handling reptiles, pet turtles, baby chicks or ducklings, or small rodents.

Beef, poultry, milk, and eggs are most often infected with salmonella. But vegetables may also be contaminated. Contaminated foods usually look and smell normal.

What are the symptoms?

Symptoms of salmonellosis include diarrhea, fever, and abdominal cramps. They develop 12 to 72 hours after infection, and the illness usually lasts 4 to 7 days. Most people recover without treatment. But diarrhea and dehydration may be so severe that it is necessary to go to the hospital. Older adults, infants, and those who have impaired immune systems are at highest risk.

If you only have diarrhea, you usually recover completely, although it may be several months before your bowel habits are entirely normal. A small number of people who are infected with salmonellosis develop Reiter's syndrome, a disease that can last for months or years and can lead to chronic arthritis.