State health officials have restricted events at the Lynden, Whatcom County, fairgrounds, where an outbreak of dangerous E. coli sickened dozens last month, to prevent potential spread of additional illness.

Dr. Scott Lindquist, the Washington state epidemiologist for communicable diseases, said the move is a precaution while county, state and federal officials determine the source of the outbreak that sent at least eight people to hospitals.

“We’re recommending they not have any more events until we’ve finished our investigation,” Lindquist said.

The request immediately affects a dog show planned for Saturday by the Mount Baker Kennel Club, expected to attract 800 canines and more than 2,000 people to the Northwest Washington Fair & Event Center.

Stiles said she understood and applauded health officials’ efforts to make sure no one else got sick at the site where more than 1,300 first-graders were exposed to Shiga toxin-producing E. coli O157: H7.

The outbreak followed the annual Milk Makers Fest held April 21-23. At least 15 people contracted lab-confirmed infections, with eight hospitalized and three who developed hemolytic uremic syndrome, a life-threatening complication of E. coli illness.

About 30 others are still being tested. Whatcom County health officials originally estimated as many as 47 people were sickened, but they’ve changed the way the cases are defined.