Two other students at Finley Elementary School have had suspicious symptoms. Health officials still are investigating the cause of the outbreak, but all the children, ages 5 to 11, ate a taco lunch Oct. 6 at Finley Elementary.
"We want to make sure no other kids have it and to get them early treatment if they do," said district Superintendent Rob Van Slyke.
The school district plans to send letters to parents today, urging them to watch for symptoms such as diarrhea and to take their children to a doctor if they suspect they are infected with E. coli.
Because the ground beef in the tacos was prepared at the cafeteria kitchen in the high school and sent to other Finley schools, officials want to get the letter to parents of all students in the district.
"The school district wants to find any way we can to preclude this happening again," Van Slyke said. "We want to issue an apology to parents who have had to suffer through this. It's a scary thing."
The cafeteria checks its meat with thermometers, and they are being inspected to make sure their readings are accurate, he said. In addition, any food service employee ill with "even a sniffle" will not be allowed to come to work, he said.
Two of the children with confirmed cases of E. coli infections were at Kennewick General Hospital on Thursday afternoon, and two more were going to be admitted to the hospital, said Dr. Larry Jecha, health officer for the Benton Franklin Health Department.
The children were in stable condition with no major complications, he said. Health department officials said the main concern was to prevent dehydration, which could lead to kidney damage.
Most of the children became ill Saturday. But tests for E. coli were not done immediately, and the health department wasn't notified of positive results until Thursday.
A family member notified the elementary school Thursday morning that a child had been hospitalized with E. coli. Principal Linda Eggers ordered school staff to call the parents of other children who were out sick, warning them flulike symptoms might mean a potentially dangerous E. coli infection.
In the afternoon, the family member of a kindergarten student notified the school that the second child tested positive for E. coli.
The health department sent investigators to the school Thursday. Working with information gathered by school officials, they identified five suspected cases of E. coli by the end of the day.
Three tests have come back positive, and another is in the process. The fifth child already has taken antibiotics, so determining if he or she had E. coli will be difficult, said Heather Hill, clinic supervisor of preventive health for the district health department.
Genetic fingerprinting is being done by the state Department of Health to confirm the cases all came from the same source. Benton Franklin Health Department officials suspect the hamburger in the meal, since ground beef often is the source of outbreaks.
The bacteria from the intestines of healthy cattle can contaminate beef in the slaughtering process. Grinding beef mixes the bacteria throughout the meat, so hamburger must be cooked all the way through to kill the bacteria.
The Finley cafeteria checks the temperature of its meat three times before it's served to children, Van Slyke said.
It's upsetting that "despite our best efforts to do things the best way and check the temperature, there is still the potential for this to happen," Van Slyke said.
Mary Ferluga, supervisor of food safety department of the county health department, said the cook who prepared the meat Oct. 6 is in the practice of cooking ground beef to well above the required temperature of 155 degrees.
One possibility for the contamination is that larger chunks of the hamburger did not get cooked completely through, Ferluga said. She did not know yet if the meat had been cooked in different batches to be sent to the elementary, middle and high school, since only the elementary school children are known to be infected.
However, the bacteria typically hits younger children harder, Hill said. And older children may not tell their parents if they have diarrhea, Ferluga said.
Some people with the infection may report mild diarrhea or no symptoms at all. But young children in particular may develop severe diarrhea and abdominal cramps.
Diarrhea often is bloody because the bacteria releases a toxin that destroys blood vessels in the intestines. The toxin then moves into the bloodstream.
Symptoms generally appear three to four days after exposure but can take as long as nine days to appear. The illness generally runs its course in five to 10 days.
Health officials are working with the families of infected children to make sure the illness is not spread to other family members. Children's nails should be clipped short, and they need to wash their hands thoroughly with lots of soap and warm water after a diarrhea episode. Ferluga suggested having them sing a song to ensure they were spending long enough at the sink to thoroughly clean any contamination off their hands.
Health officials will continue investigating the cause of the outbreak today. Also served at the lunch were tomatoes and lettuce on the taco, apple wedges, milk and a juice bar.
Sometimes in cafeterias, blood from hamburger to drip on produce on a lower shelf in the refrigerator, but that does not appear to be the case in this outbreak, Ferluga said.