What Is Shigellosis?

Shigellosis is an infectious disease caused by a group of bacteria called Shigella. The disease itself is commonly referred to as dysentery. People are the only source for Shigella bacteria.  It is extremely infectious, and ingestion of 10 organisms is enough to cause symptoms. Symptoms tend to occur within 1-3 days after ingestion.


What are the signs and symptoms of Shigellosis?

Anyone can get shigellosis. However, you are at greater risk if you:

  • are under the age of 10
  • are 60 years old or older
  • have a weakened immune system (cannot easily fight disease)

People with weakened immune systems can get a more serious illness as a severe Shigella infection can spread into the blood, which can be life-threatening.

The risk of infection is also higher for men who have sex with men. See Shigella Infection Among Gay, Bisexual, and Other Men Who Have Sex with Men | Shigella – Shigellosis | CDC

How Is Shigellosis Spread?

Shigella lives in the intestines of infected people.

Most Shigella infections are the result of the bacterium passing from stools or soiled hands of one person to the mouth of another person (fecal-oral transmission). It takes very few organisms to cause illness. As a result, person-to-person spread between family members or sexual partners is common.

People can become infected from eating contaminated food or drinking polluted water.

  • Food may become contaminated when infected food handlers do not wash their hands properly after using the bathroom.
  • Water may become contaminated if sewage runs into it.
  • Vegetables irrigated with contaminated water and shellfish harvested from contaminated water may also spread Shigella bacteria.

Flies can spread disease by being in contact with infected feces and then landing on uncovered food.


How Do You Prevent Shigellosis Infection?

  • Proper hand washing is the best prevention.
    • Proper hand washing includes soap and water for at least 15 seconds.
    • If soap and water are not available, use alcohol-based hand sanitizer with at least 60% alcohol.
    • Make sure hands are washed after using the toilet and changing diapers and before handling and eating foods.
  • Drink water from a safe supply.
    • When travelling, use bottled water or boil the water for at least 5 minutes if the water supply is unknown. Remember that ice cubes can also be contaminated. Avoid swimming in water that may be contaminated.
  • Avoid eating raw shellfish harvested from unknown sources.
  • Protect food against flies and cockroaches by keeping it covered.
  • Wash all fruits and vegetables before use.


What to do if you have symptoms of Shigellosis or diagnosed with Shigellosis

  • Get medical attention if your symptoms get worse so your doctor can test and treat you if your case is severe
  • Infected food handlers and care providers (health care, child care) should consult with their doctor about when to return to work.
  • Drink lots of fluids because you will be dehydrated as your body is losing fluid through diarrhea
  • Do not prepare food for others
  • Avoid sexual contact with others
  • Stay away public recreational water facilities like public pools, hot tubs, spas, and splash pads


This page provides basic information only. It must not take the place of medical advice, diagnosis or treatment. Always talk to a health care professional about any health concerns.


For Further Information

Call the Infectious Disease Program: (807) 625-5900

or toll-free 1-888-294-6630

Health Topic
Diseases & Infections