King County Public Health is investigating an outbreak of shigellosis at Cascade Ridge Elementary School.

The outbreak is associated with the kindergarten classes, school staff and students’ family members. At least 16 people have become sick with symptoms of shigellosis — vomiting, diarrhea and fever. Eight of those affected are children, and most have already recovered. Illness onset dates range from Nov. 4–29.

Public health investigators have not identified any common foods, restaurants or other sources among the people who got sick.

Shigellosis is an infectious disease caused by bacteria called shigella. Most who are infected with shigella develop diarrhea, fever and stomach cramps. Illness from shigella usually resolves in five to seven days, but recovered individuals may still spread the bacteria.

Environmental health investigators visited the affected kindergarten classrooms and completed an inspection of the kitchen and cafeteria at Cascade Ridge Elementary on Wednesday, Nov. 28.

The investigators did not identify any food handling practices in the kitchen that could increase the risk for shigella infection among students or staff, and no ill food workers were identified. Thorough cleaning and disinfection of common areas and surfaces was recommended and completed by the school.

Public health is continuing to work with Cascade Ridge Elementary School staff to help prevent additional people from becoming sick.

King County Public Health issued the following message:

“The investigation is ongoing and we will provide more information as it becomes available. We are working closely and cooperatively with the Cascade Ridge Elementary School staff to communicate with parents/guardians of students who may be at risk and to prevent further spread of illness. Shigella (shigellosis) can cause serious illness. If you or someone in your family works at or attends Cascade Ridge Elementary School and is currently experiencing similar symptoms, please follow-up with your health care provider and ask about stool testing. Any school staff or children that are experiencing vomiting, diarrhea, or fever should stay home from school until they have been symptom free for at least 24 hours. The spread of shigella can be stopped by frequent and careful handwashing with soap and water.”