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Public Health - Seattle & King County

Salmonella facts

What is it?

Salmonellosis is an infection of the intestines caused by bacteria called Salmonella.


Symptoms usually develop 6 to 72 hours after consuming infected food or drink. Symptoms typically last 4 to 7 days and can include:

  • Diarrhea
  • Stomach cramps
  • Headache
  • Fever
  • Vomiting
  • Dehydration (fluid loss), especially among infants and the elderly
How is it spread?

Salmonella bacteria leave the body in the stool. Persons infected with Salmonella can pass the bacteria to others if they do not wash their hands well after using the bathroom.

A person can become infected with Salmonella by:

  • Eating food or drinking water or milk that has been contaminated with Salmonella bacteria.
  • Touching infected animals and then eating or touching the mouth without washing hands first. Infected animals often do not appear sick. Animals commonly infected with Salmonella include chickens, ducks, pigs, cows, rodents, and reptiles such as snakes, lizards, and turtles. Pets are a common source of infection.
  • Eating ready-to-eat foods (foods that don't need to be cooked) that have been prepared with utensils, or on food preparation surfaces contaminated with Salmonella.
Diagnosis and treatment
  • Salmonella infection is usually diagnosed by a stool test.
  • Most people recover without treatment. Antibiotics are sometimes used for people with severe illness. Antibiotics may also be helpful for young infants and people with certain chronic medical conditions such as cancer, sickle cell disease, HIV infection, other immune system problems, and chronic gastrointestinal disease.
  • Drink plenty of liquids to prevent dehydration.
  • Wash hands with soap and warm water after going to the bathroom, changing diapers, touching animals, and before eating or preparing food.
  • Cook all meats thoroughly--particularly poultry.
  • Do not eat raw or undercooked eggs.
  • Drink only pasteurized milk.
  • Refrigerate food promptly.
  • Disinfect food-preparation surfaces and utensils after each use, as follows:
    • Use 1 tsp liquid household bleach per gallon of water.
    • Do not rinse.
    • Let air dry.
    • Prepare the bleach solution fresh daily.
  • People with diarrhea should not work as food handlers, care for children or provide health care. Children with diarrhea should not attend child care or school.

For the general public:

  • The Danger Zone
    Learn about which temperatures food should be held to prevent foodborne illnesses.

  • Picnic food safety tips
    The bacteria that cause illness grow on moist, usually protein-based foods that are between 41º F and 140º F, so minimize the time you allow these foods to stay at these temperatures.

  • Food safety fact sheets
    Chances are, you've had a food borne illness. What made you sick was a bacteria, virus or toxin in the food. Learn about other types of food borne illnesses.

For King County health care providers: