Salmonellosis (sal-mo-nel-O-sis) is a gastrointestinal disease caused by bacteria called Salmonella. This type of bacterium from infected animals is usually found in foods such as poultry, milk, and eggs.

What Is Salmonellosis?

Salmonellosis is an illness caused by Salmonella bacteria that affects the intestine, usually resulting in diarrhea. In some people, the infection spreads to the bloodstream and other areas of the body, and can be life threatening unless they receive prompt treatment.

Salmonellosis, named after the American scientist Daniel Salmon, is one of the most common causes of food poisoning in the United States. It is one of the most common foodborne diseases, with tens of millions of human cases occurring worldwide every year. According to the Centers for Disease Control and Prevention (CDC), salmonella is estimated to cause one million cases of illness in the United States each year, with about 19,000 hospitalizations and 380 deaths. Infants, the elderly, and people whose immune systems * are weakened are most vulnerable to severe infection. Salmonella strains that are resistant to antibiotics have emerged since the early 1990s and are now a serious public health concern.

The Salmonella typhimurium bacterium that can cause diarrhea.

The Salmonella typhimurium bacterium that can cause diarrhea.
CDC/Janice Haney Carr.

How Do People Get Salmonellosis?

In the United States, people usually get salmonellosis from eating or drinking contaminated food, most often raw milk or undercooked poultry and poultry products such as eggs. Undercooked ground beef or other meat can also cause salmonellosis. In some cases, food can be contaminated by the people handling it. Salmonellosis can also be spread through the feces (stool) of some pets, especially reptiles and pets with diarrhea.

A different species of Salmonella causes typhoid fever, a serious disease common in developing countries in Latin America, Africa, and Asia. Typhoid fever is spread by food and water contaminated with the bacteria. Clean water, pasteurized * milk, and effective sewage systems have made typhoid fever rare in the United States and other developed countries.

What Are the Symptoms of Salmonellosis?

The symptoms of salmonellosis include diarrhea, stomach cramps, pain, fever, headache, nausea, and vomiting. They occur within 12 to 48 hours of eating or drinking contaminated food.

How Is Salmonellosis Diagnosed and Treated?

Salmonellosis is diagnosed through stool cultures from people with symptoms of the infection. Salmonella infections usually run their course without treatment in a few days to a week after an unpleasant period of vomiting and diarrhea. Healthcare professionals suggest that people drink lots of fluids and eat a bland diet while they recover from salmonellosis. Sometimes the symptoms create other problems such as dehydration * . In those cases, people may need to go to the hospital to receive replacement fluids through their veins (intravenously, also called an IV). Antibiotics may be used if the infection spreads beyond the intestines, but salmonellosis is often resistant to drugs.

How Can Salmonellosis Be Prevented?

Thorough cooking (until poultry or meat, especially ground beef, is no longer pink and eggs are no longer runny) and regular hand washing (after using the bathroom and between handling raw meat and other foods) are the main ways to prevent salmonellosis. Only pasteurized dairy products that have been kept refrigerated should be used. Raw meat or eggs should be especially avoided.

See also Bacterial Infections • Diarrhea • Food Poisoning • Gastroenteritis • Typhoid Fever


Books and Articles

Blaser, Martin J. Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues. New York: Henry Holt, 2014.

Hylton, Wil S. “A Bug in the System: Why Last Night's Chicken Made You Sick.” The New Yorker, February 2, 2015. Available at: (accessed July 5, 2016).


Medline Plus. “Salmonella Infections.” U.S. National Library of Medicine. (accessed July 5, 2016).

National Institute of Allergy and Infectious Diseases. “Salmonellosis.” (accessed July 5, 2016).


Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 888-674-6854. Website: (accessed July 5, 2016).

Food Safety and Inspection Service. 200 Independence Ave. SW, Washington, DC 20201. Toll-free: 800-336-3747. Website: (accessed July 5, 2016).

U.S. Department of Agriculture. 1400 Independence Ave., S.W., Washington, DC 20250-3700. Website: (accessed July 6, 2016).

* immune system (im-YOON) is the system of the body composed of specialized cells and the substances they produce that help protect the body against disease-causing germs.

* pasteurize (PAS-cha-rise) is to sterilize a substance, generally a liquid like milk, by bringing it to high temperature and keeping it at that temperature long enough to destroy disease organisms in it without changing its other characteristics

* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually through sweating, vomiting, or diarrhea.

  This information is not a tool for self-diagnosis or a substitute for professional care.