Disease detectives continued tracking the source Monday of the biggest E. coli outbreak in Oregon history that has sickened as many as 42 mostly young people who attended the Lane County Fair.
Three more cases came to light Monday, bringing the number of reported E. coli cases to 42, with 36 of those confirmed cases, Lane County Public Health officials said. Four children remain hospitalized, including three in the intensive care unit at a Portland hospital.
State and county public health officials have launched an exhaustive investigation to determine the source of the outbreak. Contaminated beef and water are the most common sources of E. coli infections, but that doesn't appear to be the case here.
Investigators suspect the outbreak was caused by people visiting the animal barns at the fair, then failing to wash their hands before eating.
"Most of the sick people were in the animal barns," said Dr. Sarah Hendrickson, the county's public health officer.
Investigators haven't narrowed the source to a specific area or animal, but Hendrickson suspects goats kept in the small-animal enclosure may be the culprit.
The state's biggest outbreak before now occurred in 1993 when 39 people got sick after eating at a Sizzler restaurant in Grants Pass, said Dr. Paul Cieslak, manager of the state's communicable disease program. The first reported E. coli outbreak in the United States happened in 1982, simultaneously striking McDonald's restaurants in Jackson County, Ore., and Michigan.
The Lane County Fair ran Aug. 13-18. The incubation period for E. coli is three to seven days, so anyone infected at the fair would probably have gotten sick by now, health officials said.
Of the 42 reported cases, 26 involve people under age 18, said Karen Gillette, Lane County Public Health program manager. The oldest is 38; the youngest is 1.
Three children from the Eugene-Springfield area, all under age 2, were in serious enough condition they had to be transferred over the weekend from Sacred Heart Medical Center in Eugene to the pediatric intensive care unit at Doernbecher Children's Hospital in Portland.
One of the children, Carson Walter, a 22-month-old girl from Eugene, was briefly listed in serious condition Monday but then was returned to fair condition status, hospital spokeswoman Tamara Hargens said.
Another child, 18-month-old Ryan Keating, also was in the pediatric ICU at Doernbecher. His parents, and those of the third child asked hospital officials not to release any information about their children. Another child was still at Sacred Heart in fair condition Monday night, hospital spokesman Brian Terrett said. Two other children were released from Sacred Heart earlier in the day, he said.
All three children at Doernbecher are suffering from hemolytic uremic syndrome, Hendrickson said.
The illness often causes kidney failure and sometimes requires dialysis and transfusions, according to the federal Centers for Disease Control and Prevention. Some people develop chronic kidney failure or neurologic impairment, such as seizures or stroke. Some require surgery to remove part of the bowel.
Hemolytic uremic syndrome is the most serious illness associated with the virulent strain of E. coli, O157:H7, that sickened the fairgoers. The strain infects about 73,000 people and kills about 61 each year in the United States, according to the CDC.
State and county public health staff members are interviewing people who became sick - or their friends and family members - to find out where they were and what they did at the fair.
"Obviously, the main thing we're looking for is risk factors associated with getting sick," Cieslak said. "What did the sick people do that other people didn't do?"
Investigators also created a control group of healthy people to interview, he said. "You want a group of well people who had an opportunity to get exposure but stayed well," he said.
Investigators then do a statistical analysis to correlate risk factors. For example, if 80 percent of the sick people and none of the healthy people visited a certain animal barn, that would strongly indicate, but not prove, that barn was the source of the outbreak.
Health officials plan to take samples from the animal barns to test for E. coli, Hendrickson said.
The first E. coli case was reported last Wednesday to Lane County public health officials. Three more were reported Thursday, and the number of cases blew up over the weekend.
But only three more were reported Monday, and it's unlikely many more will be reported, Hendrickson said.
E. coli has bedeviled state and county fairs across the country in recent years.
Last year, the Ozaukee County Fair in Wisconsin had 25 confirmed cases, plus another 200 people who reported symptoms, according to newspaper accounts. State health officials linked the illnesses to people visiting the cattle barns and petting zoos, then not washing their hands before eating.
This year, Ozaukee County Fair officials took the unprecedented step of printing a warning on page one of the daily fair guide for fairgoers to wash their hands after visiting animal barns.
Lane County Fair officials also have taken steps to prevent illnesses at the animal barns. They had four hand-washing stations brought in for the 2001 fair for the first time so fairgoers could wash their hands with soap and water after visiting animals. This year, they had five stations in place, said Warren Wong, the fair's managing director.
Three of the units were in the expo building where small animals were kept, one was stationed outside the horse stables and another at the cattle tent, he said.
Fair officials will re-examine safety procedures before the 2003 fair, but the most reasonable and effective measure may be simply increasing public awareness about the importance of hand-washing after coming in contact with animals, Wong said.
Just as travelers to Third World countries know not to drink the water, fairgoers need to know they need to wash their hands, he said.
"It will be a major issue at the 2003 fair and we're going to do everything we can to make sure people have those facilities available and are cognizant that's the proper health procedure to take," he said.
Fair staff members take their obligation seriously to create a safe and health county fair, Wong said.
"Our thoughts and prayers go out to folks who got ill and their families," he said. "It's disheartening this incident occurred, yet on the other hand we try to do the best we can and hopefully this won't happen again."