Shigellosis is a disease of the gut caused by the bacterium, Shigella. There are four main species of shigella that cause disease in humans. Many of these organisms can produce toxins once inside the colon of a person. These toxins cause ulcers inside the colon, leading to the watery (and sometimes bloody) diarrhea.

Shigellosis is reportable to the Iowa Department of Public Health by Iowa Administrative Code 641 IAC 1.


The symptoms of shigellosis usually appear 1-3 days after infection occurs. Symptoms include, but are not limited to:

  • Diarrhea – watery, bloody, and/or covered with mucus; stools are often accompanied by pain
  • Fever
  • Nausea
  • Vomiting
  • Abdominal cramps


Shigella are the group of bacteria that cause shigellosis. There are four main species that cause human disease. All four of these species are found in the feces (stool) of infected people. They live inside the small and large intestines of infected people, where they damage the intestinal wall. It is this damage that leads to the characteristic diarrhea found in shigellosis.

There are three main ways that shigella are spread:

  • Person-to-Person. Any infected person can infect others by failing to properly wash their hands before handling food or coming into close contact with another person. Infections in households, pre-schools, child care facilities, and elderly and developmentally disabled living facilities commonly spread in this manner.
  • Foodborne. Flies can potentially spread the bacteria by landing on contaminated feces and then food
  • Waterborne. Fecal contaminated recreational water, such as fill and drain wading pools, can be a source for spread.

Risk Factors

Any age group can become infected with shigella. The most commonly affected groups of people are:

  • Young children, especially those in child care centers and pre-schools
  • People living in crowded conditions
  • People living in long-term care facilities
  • Men who have sex with men
  • The elderly, the debilitated, and the malnourished of all ages are particularly susceptible to severe disease and death.


Shigellosis is an extremely contagious disease. Because of this, measures should be taken to prevent its spread. Some ways to prevent infection are:

  • Thoroughly wash hands with soap and running warm water for no less than 15 seconds. This should be done every time people use the toilet, change diapers, or before they eat or prepare any food.
  • Infants and children should have their hands washed as above after a diaper change, after using the toilet, or before eating
  • Infected people should stay away from school, child care, or work while they have diarrhea
  • Food handlers, child care workers, or health care workers should consider treatment


Shigellosis is usually considered a mild infection that will go away between four to seven days without treatment. Staying hydrated and replacing electrolytes are generally considered the main treatments. However, antibiotic treatment may be necessary if the infection is severe or the infected person has a poor immune system. Antibiotics have been shown to decrease length of illness, the severity of disease, and the amount of time that the bacteria are excreted in the feces.


In 2021, 70 cases of Shigella infection were reported in Iowa. 

For more detailed information and statistics on all notifiable diseases, please see our current annual report located in the reports section of the CADE homepage.

Additional Resources


Public Health


Business and Child Care

Health Care Providers