Skip to main content
King County logo


  • Cases: 24
  • Hospitalizations: 1
  • Deaths: 0
  • Status: Investigation is completed
  • Locations: Cascade Ridge Elementary School in Issaquah
  • Prior food safety inspections and current rating?
    • N/A


Updated March 13, 2019


Public Health investigated an outbreak of shigellosis associated with the kindergarten classrooms at Cascade Ridge Elementary School in Issaquah. This outbreak appears to be over. All of the people who got sick were students, school staff, or their family members. Public Health did not identify any foods, restaurants, or other sources in common among the people who got sick.


Since November 26, 2018, 24 people became sick with symptoms consistent with shigellosis, including diarrhea, vomiting, and fever.

Fifteen of the 24 people who got sick were children, and nine were adults. One person was hospitalized, and all have since recovered. Illness onsets occurred during November 4–December 3, 2018.

Public Health actions

As part of the Public Health investigation, Environmental Health investigators visited the affected kindergarten classrooms and completed an inspection of the kitchen and cafeteria at Cascade Ridge Elementary on November 28, 2018. Investigators worked with the school nurse and principal to identify any other ill staff or students outside of the kindergarten classrooms. Our Environmental Health investigators did not identify any food handling practices in the kitchen that could increase the risk for Shigella infection among students or staff. No ill food workers were identified. Recommendations for a thorough cleaning and disinfection of common areas and surfaces was recommended and completed by the school on November 28, 2018. Public Health continued to work with Cascade Ridge Elementary School staff to help identify other ill people and prevent additional people from becoming sick.

Laboratory testing

Seven of the people who got sick tested positive for the Shigella bacteria, and five of those seven are confirmed to have Shigella sonnei. Symptoms among those who did not get tested are suggestive of shigellosis.

Report possible foodborne illness

About Shigellosis

  • Shigellosis is an infectious disease caused by bacteria called Shigella.
  • Most who are infected with Shigella develop diarrhea, fever, and stomach cramps. Some people may have no symptoms at all.
  • Illness from Shigella usually resolves in 5–7 days, but recovered individuals may still spread the bacteria.
  • Ill persons with suspected shigellosis should not work in food handling, patient care, or childcare settings, and ill children with suspected shigellosis should not attend daycare until they have seen a healthcare provider and been tested for Shigella infection, even if their illness is mild. Persons with Shigella infection who work in or attend these sensitive settings must be cleared by Public Health before returning.
  • People with mild cases of Shigellosis can still spread the infection.  It's important to have good handwashing and food safety practices at all times (see below).


General advice for reducing risk of contracting Shigella:

  1. Wash hands, cutting boards, and counters used for food preparation immediately after use to avoid cross contaminating other foods.
  2. Wash hands thoroughly with soap after using the bathroom or changing diapers, and before preparing any food or eating.
  3. Wait at least 24 hours after the last episode of vomiting and/or diarrhea before preparing any food for others.
  4. Avoid sexual activity with those who have diarrhea or who recently (within the past several weeks) recovered from shigellosis.

More information about shigellosis

Link/share this page at