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Shiga toxin-producing E. coli (STEC) associated with multiple Homegrown restaurants

Shiga toxin-producing E. coli (STEC) associated with multiple Homegrown restaurants


  • Cases: 4
  • Hospitalizations: 0
  • Deaths: 0
  • Status: Investigation is completed
  • Location: Homegrown restaurants (Redmond, Kirkland, and Seattle on Westlake Ave.)
  • Event date:April 24–26, 2018
  • Prior food safety inspections and current rating?


Updated July 2, 2018


Public Health investigated an outbreak of Shiga toxin-producing E. coli (STEC) associated with three Homegrown restaurants. We don’t have conclusive results about what caused the outbreak, but our investigation suggests it might have been a contaminated batch of pesto used exclusively on the chicken pesto sandwich.


Since May 23, 2018, we learned that four people (one is a Snohomish County resident) tested positive for STEC after consuming food from three different Homegrown restaurants in King County. Symptoms included abdominal cramps and diarrhea, with one person reporting bloody diarrhea.

All four ate the chicken pesto sandwich from one of the following locations: Redmond, Kirkland or Seattle (Westlake Ave). Of the four ill persons, three were adults and one was a child. Illness onsets occurred during April 24–May 6, 2018. Exact meal dates are not known for all four people, but known meal dates occurred during April 24–26, 2018.

Everyone who reported illness has recovered.

Public Health actions

On May 24, 2018, Environmental Health investigators visited the three Homegrown locations where the ill people reported eating. During the field inspections, potential risk factors, including handwashing facilities violations at two of the three locations, and a cold holding temperature violation at one of the three locations, were identified and discussed with the restaurant managers. Public Health did not identify any employees who experienced similar symptoms before or after meal dates for the ill customer.

We also investigated the various ingredients of the chicken pesto sandwich. All Homegrown locations in King County stopped selling this particular sandwich while the investigation was ongoing. The three restaurants were required to complete a thorough cleaning and disinfection. No employees reported working at Homegrown while experiencing illness in the three weeks prior to the illness onset dates of the customers who got sick. Investigators also reviewed the requirement that restaurant employees are not allowed to work while having vomiting or diarrhea.

Investigators revisited the restaurants on May 25, 2018, to confirm cleaning and disinfection were completed appropriately. Homegrown restaurants have been allowed to resume production of the chicken pesto sandwich at this time.

Laboratory testing

Three of the four people who got sick, tested positive for STEC O26 with the same genetic fingerprint, suggesting that they have a common source of infection; genetic fingerprinting for the other ill person could not be completed.

Pesto from each location tested negative for STEC O26. We were not able to confirm whether the pesto, another product, or another point of contamination up the supply chain caused these illnesses.

Report possible foodborne illness

About STEC

E. coli bacteria normally live in the intestines of humans and animals. Many strains of E. coli bacteria exist, and most of them are harmless or beneficial to human health. STEC are strains of E. coli that produce Shiga toxin (such as E. coli O157:H7) and can cause serious illness in people.

Infection with STEC can occur through consumption of undercooked ground beef and other beef products; unpasteurized (raw) milk, cheese, and juice; contaminated raw fruits, vegetables, sprouts and herbs; water contaminated with animal feces, or by direct contact with farm animals or their environment. Ready-to-eat foods can also be contaminated with STEC through contact with raw beef or raw beef juices in the kitchen.

Symptoms of STEC include diarrhea (which often becomes bloody) and stomach cramps, with mild or no fever. Illness typically lasts several days and people can spread infection to others even after symptoms resolve.

  • STEC infections usually resolve in 5-7 days, but recovered individuals may still spread the bacteria. Up to one third of children may continue to excrete STEC for as long as 3 weeks.

  • Ill persons with suspected STEC infection should not work in food handling, patient care, or childcare settings, and ill children with suspected STEC infection should not attend daycare until they have seen a healthcare provider and been tested for STEC infection, even if their illness is mild. Persons with STEC infection who work in or attend these sensitive settings must be cleared by Public Health before returning.


General advice for reducing risk of contracting STEC:

  • Avoid eating high-risk foods, especially undercooked ground beef and other beef products, unpasteurized (raw) milk or juice or cheese, and raw sprouts.
  • Use a food thermometer to make sure that ground beef has reached a safe internal temperature of 160° F.
  • Wash hands before preparing food, after diapering infants, and after contact with cows, sheep, or goats, their food or treats, or their living environment.
  • Thoroughly wash fresh produce before eating.

More information about STEC

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