On May 25, 2018, Public Health Seattle King County (PHSKC) announced an outbreak of E. coli O26 infections associated with Homegrown Restaurants. Four cases were reported. Three were laboratory confirmed with a genetically indistinguishable strain of E. Coli O26. The genetic fingerprint had never been seen in the United States.

All four ate the chicken pesto sandwich from one of the restaurants located in Redmond, Kirkland, and Seattle (Westlake Avenue location). Of the 4 ill persons, 3 were adults and one was a child. Illness onset dates occurring during April 24-May 6. No one was hospitalized and no one died.

On May 24 PHSKC Environmental Health investigators visited the 3 Homegrown locations where ill persons reported eating. During the field inspections, potential risk factors including hand washing facilities violations at 2 of the 3 locations and a cold holding temperature violation at one of the 3 locations were identified.