Cluster of Foodborne Shiga toxin-producing E. coli (STEC) Infections - Unknown Source

Last Updated: October 02, 2025

Three individuals have developed Shiga Toxin-Producing E. coli (STEC) infection and molecular fingerprinting suggests a common source is the cause of the infections.

In Washington

Quick Facts

  • Cases: 3
  • Hospitalizations: 2
  • Status: Ongoing
  • Recall: No

Updates

Overview

The Washington State Department of Health, Yakima Health District, and Public Health Seattle & King County are investigating a cluster of illnesses among three individuals (Yakima (2), King (1)) who developed STEC, a foodborne infection caused by certain (E. coli) bacteria. Genetic fingerprinting results (whole genome sequencing of the bacteria) indicate that these patients likely had the same source of infection. Two individuals are children (< 13 yrs of age) and one individual is an adult. Illnesses occurred between August 20 and September 11, 2025.

To date, a common food source has not been identified, and the investigation is ongoing.

About E coli

E. coli are bacteria that normally live in the intestines of humans and animals. Although most strains are harmless, some can cause illness by making a toxin called Shiga toxin. The bacteria that make these toxins are called “Shiga toxin-producing” E. coli, or STEC for short.

People usually get STEC infection by eating contaminated foods or drinks that have not been thoroughly cooked or pasteurized (heat treated). Symptoms may include diarrhea, stomach cramps, or blood in the stool. Some infected people have symptoms at all.

To prevent E. coli infection

  • Do not eat raw beef or raw or under-cooked hamburger or other ground meat products.
  • Keep ready-to-eat foods (i.e., raw vegetables) away from raw meat.
  • Drink only pasteurized (not raw) milk, milk products and fruit juices.

More Resources


To report a suspected foodborne illness or file a complaint about unsafe food handling practices at an establishment in Washington, use the Foodborne Illness Notification System (FINS).

Cases by County of Residence

County Cases
King 1
Yakima 2
Total Cases 3

Advice to Consumers

There is no specific advice to consumers at this time as a common food exposure has not been identified. Please see below for information about preventing STEC infection. 

Summary of Illnesses

One adult and one child are residents of Yakima County, and one child is a resident of King County. One child from Yakima was hospitalized.   

Public Health Actions

The investigation is ongoing.

To identify a food the infected people had in common Yakima Health District and Public Health Seattle & King County are reviewing patient records and re-interviewing the ill people and their family members. No common foods have been identified to date. We will continue to update this posting as more information is available.

Resources

E. coli facts, Foodsafety.gov

E. coli, Centers for Disease Control and Prevention

Selecting and Serving Produce, FDA

Washington State Department of Health News Release

CDC Outbreak: Packaged salads