One of the hospitalized children, a 7-year-old girl, was being transferred to Children's Hospital and Regional Medical Center in Seattle. A laboratory report showed what could be an early symptom of a kidney problem.
The three other children, all at Kennewick General Hospital, were stable Friday but being treated to prevent dehydration, which can lead to kidney failure in those infected with the bacteria.
Three of the hospitalized children had confirmed cases of E. coli poisoning, and the fourth child is believed to have the illness, although antibiotics have prevented accurate testing.
The common link seems to be tacos made with ground beef and served for lunch Oct. 6 at Finley Elementary School. The district has no reports of students at the middle or high schools getting sick, but a parent volunteer and a staff member who ate at the elementary school that day are among the 17 people who have symptoms that could indicate E. coli poisoning.
Some of the 17 potential cases being checked Friday had the bloody diarrhea that often characterizes E. coli. Others had persistent diarrhea or severe stomach cramps over several days, plus additional symptoms such as headaches, nausea or vomiting.
Health department officials can't guess yet how many people may be infected. They don't expect all those cases under investigation to test positive for E. coli. But they also suspect there are more potential cases.
Health officials continue to urge Finley parents whose children have symptoms to call the health department and see a doctor. Health district employees will be taking calls and returning messages Saturday from families concerned they may have an infected child.
The phone line will be staffed from 9 a.m. to 2 p.m. in the hope families won't wait until after the weekend to get help for their children. The number is 582-7761, Ext. 262.
Health officials will know more when they receive the results of several tests. Those include tests to confirm E. coli poisoning in those who are ill and genetic fingerprinting of the bacteria to see if the cases all had the same source.
Leftovers from the Oct. 6 lunch also are being tested for E. coli bacteria. "We were lucky there was some food left," said Mary Ferluga, supervisor of food safety services for the Benton Franklin District Health Department. Tacos made with ground beef, lettuce and tomatoes were served along with apple wedges that day.
The U.S. Department of Agriculture was sending a compliance officer to Finley on Friday. Helmut Blume, district manager for the department in Salem, Ore., said the hamburger served Oct. 6 evidently came from a plant in Nebraska but had been stored frozen for more than a year before going to the Finley schools.
The district buys USDA commodities meat.
If the meat does prove to be the source of the outbreak, a recall would be difficult because the meat was ground so long ago, he said.
Health district officials don't know why some of the hamburger might have been undercooked -cooking hamburger to 160 degrees kills the bacteria.
The Finley School District runs a lunch program with a reputation for having good compliance with safety standards, health officials said. It routinely checks the temperature of meat, usually cooking it until thermometers read well above the required minimum.
Cooking, other than reheating, is done at the high school, then food is distributed to all the district's schools.
Dr. Larry Jecha of the district health department guesses it may be just one pan of meat that went to the grade school that may have been contaminated with an undercooked chunk of beef.
Several clues point to the taco lunch. All but one person with the symptoms bought lunch at the grade school Oct. 6. In families where one child got sick and another didn't, the child who ate the school lunch was the sick one.
In addition, no symptoms have been reported in a kindergarten class that does not meet on Tuesdays, but there has been at least one illness in the kindergarten class that meets just Tuesdays and Thursdays.
Most of the children got sick Saturday, Jecha said. Painful diarrhea is common in E. coli poisoning four days after infection - the time span from Tuesday to Saturday. However, the incubation period can be as long as nine days.
One other possible source of contamination might be an employee who was ill and infected the children. But that seems unlikely, since the cases seemed to be tied to the taco lunch and the same food workers would have prepared and served food each day, health officials said.
Health district employees are concerned now about catching all the cases as soon as possible so serious complications are less likely to develop. Extreme cases, typically involving preschoolers or the elderly, may lead to kidney failure.
Families with members who may have the illness are being encouraged to be vigilant about hand washing, particularly after an episode of diarrhea, so the illness is not spread to other family members.
Adults who don't feel well should not be cooking for the family, Ferluga said.
Meanwhile, the school district is taking steps to ensure its food is safe. The health district plans a training session next week with school district employees.
In addition, thermometers are being checked for accuracy, all employees who touch food are being required to wear gloves, and food workers with even slight illnesses are not being allowed to work.
Finley parents are prepared to open an account at Key Bank on Monday to help pay the hotel and food expenses of the Voss family, whose child is being treated at Children's Hospital.
Checks may be made out to Robert and Regina Voss and mailed or dropped off at the bank's branches in Kennewick or Richland.