E. coli could have more than one source

Lab tests indicate there might be more than one source behind the 22 Escherichia coli infections reported across Northeast Tennessee and Southwest Virginia over the past two months.

Virginia Department of Health Spokesman Robert Parker said the tests revealed two different DNA fingerprints in the bacteria that has caused the recent rash of illnesses. One type was found in three of the six E. coli infections reported in western Virginia. Another type was found in a majority of the 16 E. coli cases in Northeast Tennessee. Other test results are still pending.

“The three cases match each other, but they don’t match any of the cases from Tennessee,” Parker said of the Virginia cases, explaining that the test results “make it less likely” the 22 cases in the region all came from the same source.

Still, Parker conceded, it is possible for more than one type of bacteria to come from the same source – a fact that complicates the public health investigation of the outbreak in both states.

“This is all just part of the puzzle,” Parker said as he delivered this week’s E. coli update. “It just means it’s the same type of bug and we still have no evidence that it came from a common source.”

The outbreak

Eighteen people in the region were diagnosed with E. coli infections between May 8 and June 11 – including a 2-year-old Dryden, Va., girl who died June 5. The number of cases reported in such a short period of time raised an alarm for public health officials in Virginia and Tennessee. During all of 2010, the region saw a total of 17 E. coli cases and no deaths.

The recent rash of infections are all from a deadly form of E. coli known as STEC or Shiga toxin-producing E. coli. The toxins produced by this strain of the bacteria can cause severe abdominal cramps, bloody diarrhea, vomiting and a low-grade fever lasting five to seven days. But in the very young and the very old, STEC infections can lead to hemolytic uremic syndrome – a rare medical condition that wipes out the body’s red blood cells, causes short-term kidney failure and can kill children and adults.

Since those initial 18 cases were reported, four more of the regions residents have been diagnosed with E. coli infections. At least two might have acquired the bacteria from contact with someone else who was infected.

The investigation

Northeast Tennessee Regional Health Office Director David Kirshke reported last week that his office confirmed that the two most recent E. coli victims from Sullivan County, Tenn., had previous contact with another E. coli victim. Those two patients started showing symptoms June 20 and June 26.

Those cases are considered secondary spread, Kirshke said, because the victims contracted the illness from exposure to a previous E. coli victim and not the original source of the bacteria.

That means there has only been one “new case” from Northeast Tennessee, he said. That patient started getting sick June 23.

But health officials aren’t sure yet which specific strain of E. coli they’re dealing with in that most recent case, the 15th in Northeast Tennessee.

So far, health officials in both states have identified at least four different strains of the bacteria in the rash of infections – but they haven’t seen all of the test results.

Kirshke’s office is still waiting on results from the U.S. Centers for Disease Control and Prevent regarding a series of E. coli cases that sickened five Northeast Tennessee residents May 14, May 16, May 23 and May 28. Preliminary tests completed by his office show the bacteria in these cases were from a non-O157 E. coli strain such as E. coli O103:H11, O69:H11 or O103:H2.

Kirshke’s office cannot determine exactly what type of strain is at work in those cases, which is why cultures of the bacteria involved in the infections were sent to the CDC. But the federal health agency is facing a backlog of E. coli testing, because outbreaks of the illness also have been reported in four other states – Alabama, Idaho, Texas and Oklahoma.

“They told me not to hold my breath,” Kirshke said, adding that he was told it could be several months before he gets his test results – a delay that will hinder his attempts to determine why so many people are getting sick in such a short amount of time.

The people

Gabby Blair, the 2-year-old who died from an E. coli infection June 5, was rushed to the Johnson City Medical Center’s Pediatric Intensive Care Unit after she and her brother began suffering severe diarrhea and vomiting. Five-year-old Lazarus Blair is now in good health after several days of medical treatments at the Vanderbilt University Medical Center in Nashville.

Parker said the children are among a group of five western Virginia residents who contracted E. coli between May 8 and June 11. All five were infected by a strain known as O157:H7, which is behind 36 percent of the 265,000 STEC infections that occur in the U.S. each year.

During that same six-week period of time, officials with the Northeast Tennessee Regional Health Office reported STEC infections in nine residents of its service area of Carter, Greene, Hancock, Hawkins, Johnson, Unicoi and Washington counties.

The Sullivan County Regional Department of Health reported two more cases during that period as well.

Abingdon resident Zoey Weaver, 5, became the region’s 19th E. coli victim when she started showing symptoms of an STEC infection June 19 and was rushed to the Vanderbilt University Medical Center when she developed hemolytic uremic syndrome.

“She’s doing better today,” Zoey’s father, John Weaver, said Sunday in a telephone interview from her hospital room at Vanderbilt. “It’s still just a waiting game. Doctors told us, this just takes time.”

Weaver said his daughter hasn’t needed a blood transfusion since Wednesday. While she is still on dialysis 24 hours a day, he said, she has started urinating on her own and that is a good sign her kidneys are regaining function.

gmclean@bristolnews.com

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