Tracking the German E. coli outbreak: a Northwest connection

Washington and Oregon scientists have been closely monitoring strains of E. coli since the deadly Jack in the Box outbreak here in 1993. The experts now wonder: Is Europe dealing with a deadly new version of the bug?

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Washington and Oregon scientists have been closely monitoring strains of E. coli since the deadly Jack in the Box outbreak here in 1993. The experts now wonder: Is Europe dealing with a deadly new version of the bug?

“New SuperToxic Strain,” shouts the headline from Britain’s Sky News. “Germany Wrestles with Deadly E. Coli,” reports the Los Angeles Times. “A Warning for Americans,” lectures Fox News.

Some two weeks after the onset of Germany’s E. coli outbreak, the world media have begun to take notice. Editors from organizations ranging from Public Broadcasting and The New York Times to Bloomberg and CBS News are dispatching reporters to Germany in hopes of unraveling the mysteries of E. Coli O104:H4.

Even The Wall Street Journal weighed in, having observed “economic and diplomatic disruptions” from the outbreak.

For health authorities in the Pacific Northwest, who have been tracking E. coli outbreaks dating back to Jack in the Box in 1993 and beyond, all this newfound attention is good news and bad. On one hand, they hope the media coverage will provide some of the information they need to answer their own questions about the German outbreak.

But the bad news, they say, is that the feverish pitch of the reporting threatens to make the European epidemic look like a bad 1950s science-fiction movie, complete with a mutant monster crawling out of a dismal swamp.

Escherichia coli O104:H4, the toxic bacteria being blamed for the epidemic, appears to be a new strain of E. coli, according the World Health Organization. But epidemiologists, who make their livings monitoring these bugs, caution that much more needs to be known before deciding if they have a monster on their hands.

Viewed under a microscope, E. coli O104:H4 lacks charisma — no fangs, no claws, no growls. It is indistinguishable from scores more varieties of mostly harmless E. coli that inhabit the guts of humans and other warm-blooded animals. It is part of a vast family of bacteria that are rod-shaped — long and skinny — with one or more whip-like flagella, used as a sort of propeller, which may or not be visible even under the microscope. The same, vast family of bacteria also includes Salmonella and, for that matter, Yersinia, which causes the plague.

The numbers — O104:H4 — carry no meaning. They are merely assigned by scientists when new strains are identified. While E. coli get numbers, each strain of Salmonella gets a name — Salmonella Saintpaul or Salmonella Heidelberg — which some scientists find easier to remember.

But, despite its prosaic appearance, E. coli is a stunningly complex organism that has intrigued scientists for nearly 200 years — that is, since microscopes were available to study the bugs. Each tiny E. coli is managed by a genome composed of 5.2 million pairs of genes — genes that control every imaginable facet of the bug, for better or worse. When that genome was sequenced, nearly 15 years ago, it was a scientific milestone.

Whatever their genetic code, E. coli thrive in the warmth of the human gut. There they perform a variety of services, such as assisting with digestion. They also reproduce at a phenomenal rate, as quickly as every 20 minutes. When an organism reproduces that fast, it is capable of evolving far more quickly, so that a mutation can find its biological niche in weeks or months, rather than years or eons.

Some 30 years ago, health authorities in Washington and Oregon became leaders in the business of tracking these microbes, including the notorious E. coli O157:H7, a strain that lives in the intestines of cows, and that carries a highly poisonous shiga toxin. Bugs are shed in cow manure, which can contaminate milk or ground beef or vegetables growing nearby. If passed along to humans, E. coli O157:H7 causes severe diarrhea and, in about 10 percent of cases, a potentially fatal complication, hemolytic uremic syndrome, or HUS.

That strain has been the cause of most serious outbreaks of E. coli poisoning, from the one that began with Jack in the Box hamburgers to the spinach and cookie-dough outbreaks of recent years.

For years, scientists have debated whether E. coli O157:H7 is a newly-evolved strain, or whether it has been poisoning people for centuries, without being detected by science. That debate continues.

And now a similar discussion is likely to develop around E. coli O104:H4. 

There is ample evidence to support the idea that the German bug is new. Scientific literature offers only one previous mention: a small outbreak in Korea in the mid-1990s. (An outbreak of E. coli O104:121 in Montana in the mid-'90s was, despite the similar coding, unrelated.) Two different research companies, in China and Germany, have sequenced the genome of the outbreak strain, and both concluded that it is new.

Some health authorities cite the epidemic statistics as further evidence of a new and dangerous strain of bacteria. The German outbreak has sickened at least 1,600 people, 500 of them with life-threatening HUS — numbers that already make it one of the worst known outbreaks in recent history. In addition, the epidemic has sickened mostly adult women — an unusual pattern for E. coli outbreaks.

Those statistics may help German officials trace the epidemic to its source, explains Dr. Bill Keene, a respected foodborne illness specialist with the Oregon Health Department. But it probably says little or nothing about the nature of the bug itself — including whether it is a new strain, Keene adds. 

And, while the number of potentially fatal HUS cases appears to be three or four times higher than usual, that depends on an accurate count of the overall number of illnesses, Keene explains. It’s quite possible that far more people were sickened in Germany, and that a small proportion have been reported to health authorities.

Either way, he and other health authorities across the U.S. and around the world are monitoring events as they unfold in Germany, wondering if they will soon be dealing with yet another microscopic monster.

This article first appeared on foodsafetynews.com and is reprinted with permission.

  

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About the Authors & Contributors

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Ross Anderson

Ross Anderson is a former Seattle Times reporter who now lives in Port Townsend.