E. coli outbreakPosted: June 18, 2011
Europe is currently in the grip of a deadly outbreak of Escherichia coli O104:H4—a rare strain of a common bacterium. Prior to last month, E. coli O104:H4 had only been identified as a cause of illness in one, single person. As of yesterday, the bacteria had sickened thousands and killed 27.
E. coli is a gut bacteria. There are E. coli living in your intestines right now. The good news is that those strains aren’t dangerous. Instead, when people get sick from E. coli, it’s usually the work of strains that live in the guts of animals, especially cows. These bugs, while as friendly to their bovine hosts as our E. coli are to us, release chemicals that are toxic to people. When we consume them—by getting meat juices on fresh vegetables or fruit, via manure sprayed on crops, or through contaminated water supplies—the foreign E. coli can make us very, very sick. And that sickness is difficult to treat. That’s because some strains, including O104:H4, actually release more toxins when you try to fight them with antibiotics.
The European Center for Disease Prevention and Control has linked most of these recent cases back to the northern part of Germany, the victims either live there or had recently traveled through the region. So it’s reasonable to assume that the contaminated food either came from there, or was eaten there. But that’s the easy part. It’s much, much harder to figure out what, exactly, it was that made people sick. Over the weekend, authorities thought they’d pinpointed the outbreak to a bad batch of organic salad sprouts. But, when preliminary tests of the sprouts turned up no evidence of contamination, they backed off and started pointing the finger at imported cucumbers and tomatoes from Spain. Today, the official opinion flip-flopped again. Direct tests of the sprouts are still turning up negative. But epidemiological studies show that people who ate the sprouts were 9 times more likely to become infected than those who had not.
That’s enough evidence to affect the immediate public health response—shut down the farm, warn people off sprouts. But it’s not necessarily going to be the final word on where this outbreak came from.