An E. coli outbreak linked to locally produced organic yogurt is growing, with 15 people now confirmed infected. Eleven of the patients are children.

Washington State health officials report nine of the patients have required hospitalization and four have developed the potentially deadly kidney complication known as hemolytic uremic syndrome (HUS). No deaths have been reported as of the health department’s May 26 update.

“The outbreak is likely linked to PCC Community Market brand yogurt produced by Pure Eire Dairy,” according to the updat and information previously reported by state and local officials. The dairy also produces organic yogurt under the Pure Eire brand.

On May 15, the Washington Department of Health announced the likely link to the yogurt and Pure Eire Dairy issued a voluntary recall of all of its yogurt sold under any brand name. 

“Anyone who has PCC Community Market or Pure Eire brand yogurt at home should not eat it and should throw it away. The investigation is ongoing, and we may identify additional links to products as we continue to gather information from new cases,” according to the state health department.

The investigation process is long and complex. only those who are severely ill tend to visit a healthcare provider and get tested, and each step of the process takes time.

Sometimes people don’t get sick until several days after they eat food containing E. coli bacteria. It can take weeks to test samples from people who are ill, confirm those tests, interview patients for a detailed history of foods they’ve eaten, and look for commonalities between cases, the health department updat states.

Of the patients confirmed as of the update, nine are younger than nine years old. Two are 9 to 19 years old. The rest are between 20 and 79 years old. The health department did not report which patients have been hospitalized, but it is known that the four patients with HUS are all children.

All of the confirmed patients are in Washington State, except one child from Arizona who has developed HUS. Relatives from Washington visited the family in Arizona before the child became ill.