Salmonella Infections

Written October 2006; updated June 2008.

What Is Salmonella?
Symptoms of Salmonella Infection
Preventing Infection

What Is Salmonella?

Salmonella bacteria can be found in many different places and in a variety of animal species. Salmonella can most frequently be found in foods such as raw meats, particularly poultry. It can also be transferred to soil, water, and kitchen surfaces through contamination.

Symptoms of Salmonella Infection

The CDC estimates that 1.5 million people per year are affected by Salmonella-related illnesses. Salmonella infection causes cramps, diarrhea, fever, headache, nausea, and vomiting. Symptoms usually develop within three days of eating contaminated food. Without treatment, most people experience full recovery within one week, but some people--particularly children and the elderly--may take longer to recover.

Infections are usually mild, but can result in severe illness or death in certain at-risk individuals--children, the elderly, the immunocompromised, and pregnant women. The CDC estimates that Salmonella-related illnesses are responsible for approximately five hundred deaths each year. If you experience severe symptoms, you should seek medical attention as soon as possible.

A small number of people infected with Salmonella may develop reactive arthritis--a chronic long-term illness. Arthritic symptoms can begin three to four weeks after the Salmonella symptoms. Reactive arthritis--a potentially debilitating illness--can last for at least six months and even longer.

Preventing Infection

Keep It Clean

Good personal hygiene is the most important part of preventing foodborne illness. Wash your hands with warm, soapy water before preparing food, and wash frequently while cooking, especially if you are working with raw meat.

Fresh vegetables and fruits should be washed thoroughly before being eaten or cooked. Wash your hands between touching raw meat and other foods.

Keep Foods Separated

Use separate cutting boards and utensils for uncooked products. Keep raw meat separated from produce, cooked food, and other food products. Wash your hands, utensils and other kitchen tools, and counters before and after working with uncooked food.

Cook Food Thoroughly

Make sure that meat and foods containing meat are cooked thoroughly before you eat them.

Use pasteurized egg products when recipes call for raw eggs.
Cook eggs, fish, meat, or foods containing these items to a minimum internal temperature of 155°F for at least 15 seconds.
Cook ground meat products to a minimum internal temperature of 155°F for at least 15 seconds.
Cook poultry to a minimum internal temperature of 165°F for at least 15 seconds.
Reheat previously cooked foods to a minimum internal temperature of 165°F.

Store Food Properly

Proper food storage helps prevent foodborne illness. Cooked food should not be left at room temperature for more than two hours before being refrigerated again. If you are not sure how long the food has been sitting out, throw it away.

Use the following tips to make sure that frozen food is stored and thawed safely.

Keep frozen foods in the freezer until you are ready to cook them.
Frozen food should be thawed in the refrigerator or under cold running water. Do not let meat thaw on the kitchen counter!
Frozen food can also be thawed as part of the cooking process.

Recent Outbreaks

On June 7, 2008, the U.S. Food and Drug Administration (FDA) issued an alert that a nationwide salmonellosis outbreak appears to be linked to eating certain types of raw red tomatoes and products containing raw red tomatoes. The bacteria causing the illnesses are Salmonella serotype Saintpaul, an uncommon type of Salmonella.

The specific type and source of tomatoes are under investigation, but raw red plum, raw red Roma, or raw round red tomatoes are believed to be the cause. At this time, consumers should eat only tomato varieties that have not been implicated in the outbreak: cherry tomatoes, grape tomatoes, tomatoes sold with the vine still attached, and home-grown tomatoes.

For more information about this outbreak--such as the status of the investigation; how to report complaints; a list of states, territories, and countries not associated with the outbreak; and other topics--visit the FDA's outbreak update Web page.

For answers to other common questions about the origins and spread of Salmonella and what scientists are doing to ensure the safety of produce, read Salmonella & Tomatoes: Q&A for Consumers.