They are among six Clark County children ages 5 to 14 who apparently have come down in the past week with E. coli 0157:H7, a strain that can cause death or serious kidney damage, said Dr. Justin Denny, Clark County health officer. Four cases have been confirmed and the remaining two appear likely to be the same strain, he said.
The severely ill children are in Portland-area hospitals; the other four are recovering at home.
The common source of the disease could be raw milk from Dee Creek Farm in Woodland, Denny said. Health officers confirmed Monday that five of the six consumed unpasteurized milk -- milk that has not been heated to kill bacteria it contains -- from the farm.
"That doesn't close the door, but it's pretty strong evidence," Denny said.
The incubation period for fecal-related E. coli 0157:H7 is usually about three days but can be as long as 10 days.
Denny urged people not to drink unpasteurized milk. "The risks far outweigh" the taste, he said.
Anyone who has drunk unpasteurized milk and has bloody diarrhea or diarrhea of any kind should seek medical attention, he said.
Denny also urged people to wash their hands after using the toilet to avoid spreading fecal bacteria that can cause E. coli.
Denny said he is working through the Washington Department of Agriculture and the Cowlitz County Health Department to contact the farm regarding the illnesses and the risks of producing raw milk.
The number of cases of the virulent E. coli strain is growing in Clark County, with 25 reported this year, he said.