Causes of shigellosis (Shigella)

Learn about the causes of shigellosis, how it's spread and where it's found.

On this page

• Cause of shigellosis
• How shigellosis is spread
• Where shigellosis is found

Cause of shigellosis

Shigellosis is an illness of the intestines caused by bacteria called Shigella.

How shigellosis is spread

Shigellosis is easily spread and you can become infected by:

• eating contaminated foods
• drinking contaminated liquids, including:
  • drinking water
  • other drinks
  • recreational water such as rivers, lakes and other coastal waters
• touching contaminated surfaces, such as:
  • diaper pails
  • bathroom doorknobs
• exposure to the feces of an infected (or recently recovered) person during sexual activity, including direct or indirect oral-anal contact
• swimming and bathing in contaminated recreational waters, such as:
  • lakes
  • swimming pools
• touching your food or your mouth with hands that have become contaminated by:
  • changing the diaper of an infected child
  • caring for an infected person who may have the bacteria on their hands or body

How food and water become contaminated

Food can become contaminated with Shigella when:

• it's handled by a person who:
  • didn't properly wash their hands after touching:
    • contaminated foods
    • animals or animal environments, including food and treats
  • is infected with Shigella and didn't properly wash their hands after using the bathroom
• it's prepared on a surface that came into contact with other foods or water contaminated with Shigella
  • cross contamination can happen because of unsanitary food handling practices
• it comes into contact with contaminated manure or water when it's grown and harvested
• flies spread the bacteria from contaminated feces to uncovered foods

Foods that have been found to be contaminated with Shigella include:

• unpasteurized milk
• fruits and vegetables
• raw oysters and shellfish
• prepared salads, including:
  • fruit
  • tuna
  • pasta
  • potato
  • lettuce
  • chicken

Water, including untreated drinking water, can become contaminated with Shigella. This happens when feces from infected people or animals enter the water supply.

Where shigellosis is found

Shigella is naturally found in the intestines of humans.