Causes of salmonellosis (Salmonella)

Learn about the causes of salmonellosis, how it is spread and where it is found.

On this page

• What causes salmonellosis?
• How is salmonellosis spread?

What causes salmonellosis?

Salmonellosis is an infection caused by Salmonella bacteria.

How is salmonellosis spread?

Salmonellosis can be spread when you eat or drink contaminated food or beverages, such as:

• raw or undercooked poultry, pork and ground beef
• raw or undercooked eggs or egg products
• unpasteurized dairy products like raw milk and cheese
• raw fruits and vegetables

It can also be spread if you have contact with:

• infected animals, such as:
  • birds
  • reptiles
  • livestock
  • amphibians
  • dogs and cats
  • small pets like:
    • gerbils
    • hamsters
    • hedgehogs
    • other rodents
• a person infected with the Salmonella bacteria
  • you can be contagious from several days to several weeks
• foods or surfaces contaminated by the bacteria
  • practice proper food handling practices to reduce transfer of Salmonella bacteria between foods
• contaminated pet treats and food (raw or processed, both wet and dry)
  • a pet can get salmonellosis from contaminated food and spread it to you
  • you should wash your hands after:
    • touching pets
    • cleaning up after pets
    • touching pet food, treats or toys
  • if it is handled by a person who:
    • did not properly wash their hands after touching:
      • contaminated foods
      • animals or animal environments, including food and treats
    • is infected with Salmonella and has not properly washed their hands after using the bathroom
    • has prepared food on a surface that came into contact with other foods contaminated with Salmonella
  • during the butchering and processing of raw meat
  • during the growing or harvesting of fruits and vegetables
    • contamination is possible if the produce comes into contact with contaminated manure or water

Both animals and people can be carriers of salmonellosis. This means they are infected with Salmonella and can spread the illness to others without showing signs of sickness.

Where is it found?

Salmonella bacteria are commonly found in the intestines of animals and birds.

How do food and water become contaminated?

Water can become contaminated with the bacteria when feces from infected people or animals, including carriers, enter the water supply.

Food can become contaminated with Salmonella:

• if it is handled by a person who:
  • did not properly wash their hands after touching:
    • contaminated foods
    • animals or animal environments, including food and treats
  • is infected with Salmonella and has not properly washed their hands after using the bathroom
  • has prepared food on a surface that came into contact with other foods contaminated with Salmonella
• during the butchering and processing of raw meat
• during the growing or harvesting of fruits and vegetables
  • contamination is possible if the produce comes into contact with contaminated manure or water