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Little known about rare E. coli strain behind European outbreak

In this handout photo provided by the Helmholtz Center for Research on Infectious Diseases an EHEC bacteria is visible on May 30, 2011 in Berlin, Germany.

Handout/Getty Images

As global health officials linked a deadly European E. coli outbreak to a previously unseen mutation of the bacteria, scientists warn that there are more, equally rare strains that could cause chaos.

Until now, experts have associated the most serious outbreaks of food-borne E. coli to a well-known strain of the bacteria called O157:H7. It has turned up in processed beef, bagged salad greens, walnuts, sprouts and water. Ingesting food contaminated with the strain can be life-threatening because it produces harmful Shiga toxins - antibiotic-resistant bacteria that can trigger bloody diarrhea and organ failure via hemolytic uremic syndrome, or HUS.

As a result, scientists, academics, food companies and governments have focused on perfecting their testing and detection of the entire O157 family - H7 being one of its many permutations. Beyond their focus, a string of lesser-known E. coli families have begun to wreak deadly havoc. Like O157, the lower-profile strains also produce Shiga toxins, which doctors battle against. Other than the names of these new strains, scientists know very little about them.

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That includes the rare strain, E. coli O104:H4, implicated in the German outbreak. It has killed at least 18 people, sickened more than 2,000 others and set off a panic among concerned scientists who fear research has fallen behind.

"We need to get the knowledge gaps filled and develop detection techniques," said Keith Warriner, a director in the department of food science at the University of Guelph. "Unless we get the same level of knowledge we have for O157, these outbreaks will just keep happening. This one is bad enough."

While E. coli typically fells the very young, the elderly or people with weakened immune systems, the German strain has mainly affected middle-aged adults, two-thirds of whom are women. Like other types of E. coli, the strain has been highly resistant to treatment.

Over the past five years, similar forms of E. coli have proved fatal. Four people were killed and 70 sickened this year in Japan from beef contaminated with a family of E. coli called O111. In 2008, the same strain killed one person and sickened 344 more in Oklahoma. One person died and 18 became sick in Norway from a related strain from tainted sausage in 2006.

Mr. Warriner said these strains cannot be treated the same as better-known E. coli families such as O157 until investigators are sure of their origin, means of survival and transmission.

The U.S. Department of Agriculture's Food Safety and Inspection Service recently developed tests that will detect six of the dangerous new Shiga toxin-producers. While tests for O157 are mandatory for ground beef, testing for other harmful strains of the bacteria, such as O1111, are not.

Last year, the agency was petitioned to declare the additional disease-causing strains of E. coli "adulterants," which would make the bacteria illegal and trigger official testing. The petition remains under review.

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Still, the USDA test would not have picked up the form of E. coli ravaging Europe because the strain lacks a protein that other harmful strains have, which is critical for positive test result.

Mr. Warriner, who recently applied for a grant to study the lesser known forms of dangerous E. coli., said the sudden scourge caused by O104 is "right out of the blue."

"Nobody thought it could do something like this," he said.

There is only one other recorded case of a related O104 strain causing food-related illness: In 1994, 18 people in Montana were sickened after drinking contaminated milk.

European health officials are struggling to determine the cause of the German outbreak, as well as the vehicle spreading it. The European Centre for Disease Prevention and Control exonerated Spanish cucumbers thought to be responsible for the outbreak, which surfaced May 22, but said in a statement Thursday that some form of contaminated food is still a likely culprit.

The acceleration of the outbreak worries Mr. Warriner, but if there is a silver lining to the situation, he said, it is the increased scientific interest in E. coli the situation will generate. "With this outbreak ... things are going to change."

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The pain in Spain

Farmers find it hard to spring back after mistaken E. coli fears cripple exports

When health officials in Hamburg, Germany claimed last week that cucumbers from Spain had caused a massive E.coli outbreak in the city, the news hit Spanish farmers hard. Exports of fruits and vegetables dried up instantly, prices plunged more than 40 per cent and roughly 70,000 farm jobs were jeopardized.

There was just one problem: Tests later proved that Spanish cucumbers were completely safe. Hamburg officials offered a mea culpa this week but the damage had already been done. Spanish farmers estimate they have lost €200-million (nearly $283-million) in business and that German stores are still reluctant to take their products. It's a tough blow to Spain's main agricultural regions, Valencia and Andalusia, where unemployment is already hovering around 30 per cent.

The dispute has fractured the EU and raised questions about how it handles these kinds of health issues. All 27 member countries agreed to a common declaration on May 31 that called on Germany to identify the source of the contamination and provide information to other members through the EU's rapid alert system. But there are now questions about Germany's slow response and its initial decision to single out Spain and slap on trade restrictions. That strikes at the core of the EU, which is supposed to unify trade rules between members.

Paul Waldie

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About the Author
Global food reporter

Jessica Leeder is the Globe’s Atlantic Reporter, based in Halifax, Nova Scotia. In previous roles, Jessica has reported for the Globe from Afghanistan and post-quake Haiti, assignments for which she won an Emmy and a National Newspaper Award, respectively. She has also written about the politics of global food, entrepreneurialism and small business, and automotive news. More

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