LOS ANGELES (Reuters) - An outbreak of E.coli cases in northeastern Tennessee and southwestern Virginia has sickened 13 people and resulted in the death of a young child, public health officials said on Friday.
Virginia has two confirmed cases of the E.coli strain O157:H7, which can cause severe illness -- particularly in young children and the elderly. The same strain caused a 1993 E.coli outbreak that killed four people who ate tainted hamburgers from the Jack in the Box fast-food chain.
Both Virginia cases affected children who had close contact with each other, and one of those children died, said Maureen Dempsey, a Virginia Public Health Department deputy chief.
Dempsey declined to confirm the age and sex of each of the children, but local media reported a 2-year-old girl from Dryden, Virginia, died on Sunday and her brother, who was also infected, was released from a hospital a few days later.
Northeastern Tennessee has 11 laboratory-confirmed cases of E.coli since June 1, said David Kirschke, medical director of the Northeast Tennessee Regional Health Office.
"That's as many cases as we had all of last year," he said.
Three cases were O157:H7, and the remainder other strains in a category known as non-O157, he said. Kirschke said no link has been made between the Virginia and Tennessee cases.
"We're not even sure if our cases are linked with each other," he said, adding the Tennessee O157:H7 strains also are being genetically fingerprinted to see if they are from a single source.
Still, Kirschke said health officials are treating the cases as an outbreak due to their large number, their close proximity and the short time frame of their appearance
"It seems too coincidental to have this many cases in a week," he said.
Public health officials underscored that the E.coli strains in Virginia and Tennessee are different from the one behind the deadly outbreak in Germany. That outbreak is being blamed on a rare strain of Shiga toxin-producing E.coli known as O104:H4.
The U.S. Centers for Disease Control and Prevention is looking into whether there have been previous spontaneous outbreaks of different strains of E.coli, Kirschke said.
The source of the Virginia and Tennessee infections has not yet been pinpointed, but E.coli is commonly spread through contaminated food or water.
Hamburger, unpasteurized (raw) milk and raw produce have been linked to prior outbreaks, as has water from lakes, streams and swimming pools.
Symptoms of E.coli infection vary from person to person but often include severe stomach cramps, diarrhea (often bloody), and vomiting. If there is fever, it usually is mild (less than 101°F/38.5°C). Most people get better in five to seven days.
Up to 10 percent of patients develop a serious complication known as hemolytic uremic syndrome, or HUS, which frequently leads to kidney failure and can result in death.
The incidence of E.coli O157:H7 infection in the United States fell by roughly half between 1997 and 2010, according to Vital Signs, an annual food safety report that summarizes CDC data. Last year, there were 442 confirmed cases of O157:H7, which resulted in 184 hospitalizations and two deaths, according to that report.
CDC attributed the drop to improved animal slaughter methods, testing, better inspections and other efforts.
Meanwhile, the CDC said there was a nearly 58 percent rise in non-O157 E.coli infections from 2009 to 2010. There were 451 confirmed cases of non-O157 last year, resulting in 69 hospitalizations and one death.
CDC estimates one in six people in the United States gets sick from eating contaminated food each year. Food-borne illness is blamed for about 3,000 U.S. deaths annually.
Editing by Steve Gorman and Jerry Norton