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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. The infection can spread from the intestines to the blood stream and other body sites.

What are the symptoms?

  • Symptoms usually develop 12 to 72 hours after infection. 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
  • Salmonella infection can be severe in persons with weakened immune systems.

How is it spread?

  • Salmonella bacteria leave the body through the stool of infected people and animals. Others become infected when hands, food, or objects contaminated with infected stool are put in the mouth.
  • 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.
    • Eating or touching the mouth after touching infected animals 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 on food preparation surfaces or with utensils contaminated with Salmonella.

How is it diagnosed and treated?

  • Salmonella infection is usually diagnosed by testing the stool for the bacteria.
  • 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.
  • Drinking plenty of liquids is recommended to prevent dehydration.

How can salmonellosis be prevented?

  • Thorough hand-washing is the best way to prevent spread of infectious diseases of the intestinal tract.
  • Wash hands with soap and warm water after going to the bathroom, changing diapers, touching animals, and before eating or preparing food.
  • Do not allow reptiles in areas where you feed or bathe small children.
  • Keep reptiles and amphibians out of homes with children younger than 5 years old or people with weakened immune systems.
  • Cook all meats thoroughly, especially poultry.
  • Do not eat raw or undercooked eggs.
  • Drink only pasteurized milk.
  • Defrost meat and poultry in the refrigerator rather than at room temperature.
  • Refrigerate food promptly.
  • Wash cutting boards and counters used for meat or poultry preparation immediately after use to avoid cross contaminating other foods.
  • Do not swim in pools or lakes if you have diarrhea.

NOTE: People with diarrhea should not prepare or serve food or beverages to others, provide child care, 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: