Health officials: E. coli outbreak in King County has spread to Snohomish County Deedee Sun, KIRO 7 News Staff Snohomish County health workers said Tuesday an E. coli outbreak in King County has now spread to the North Sound. Last week, Public Health — Seattle & King County is investigating a cluster of toxic E. coli cases that left seven children infected during a two-week period. Six of them had to be hospitalized. The children, all under 14, were infected with Shiga toxin-producing E. coli., also known as STEC. The cases were reported between April 22 and May 1. Three of the children are under 5 years old.