Shigellosis

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. Shigella are extremely infectious bacteria, and ingestion of just 10 organisms is enough to cause symptoms.

How could I get shigellosis?

You can get Shigella infection when the bacterium is passed from stools or soiled hands of one person to the mouth of another person (fecal-oral transmission). It takes so few organisms to cause illness therefore person-to-person spread between family members is common.
You can also get Shigella infections from eating contaminated food or drinking contaminated 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.

What are the symptoms?

Most people who are infected with Shigella develop diarrhea, fever and stomach cramps. The diarrhea is often bloody. Symptoms can start as early as 12 hours after being exposed to the bacteria but could take up to 4 days. Illness usually resolves in 4 to 7 days. Some people may have only mild infection or no symptoms at all.

When is an infected person contagious?

The person is contagious while having symptoms and up to 4 weeks after symptoms resolve.

 How can you prevent shigellosis infection? 
 

• Thorough hand washing is the best prevention. Make sure hands are washed after using the toilet and changing diapers and before handling and eating foods. 
• Infected people should not work as food handlers or care providers until their symptoms have resolved and they have had 2 negative stool samples taken 24 hours apart.
• Drink water from a safe supply. When traveling 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. 
• Wash all fruits and vegetables before use. 

 
For more information please contact 1-800-958-6400 or the local Public Health Nursing
Office.
April 2018