Skip to Content

Old Fashioned Epidemiology Pegs Sprouts in E. Coli Outbreak

Scientists are still searching the genome for clues to its unusual virulence.
June 10, 2011

German authorities confirmed on Friday that bean sprouts were responsible for the deadly E. coli outbreak that has now killed 30 people.

While sprouts had been named as a possible source earlier in the week, public health authorities took back that indictment after lab tests came back negative.

But now, thanks to old-fashioned epidemiological investigation, sprouts have been definitively named the culprit. By interviewing patients and chefs at restaurants where infected people had eaten, investigators found that people who had eaten bean sprouts were nine times more likely to get infected than those who hadn’t, said Reinhard Burger, head of Germany’s disease control agency, at a news conference in Berlin on Friday.

According to a report from the Associated Press, “The breakthrough in the investigation came when a taskforce linked patients who had fallen ill to 26 restaurants and cafeterias that had received produce from the organic farm.”

Authorities also said it is now safe to eat tomatoes, cucumbers and lettuce, which had all been previously implicated in the outbreak.

Researchers in Germany and China sequenced the E. coli strain responsible for the outbreak in record time, thanks to new sequencing technology from Ion Torrent, a start-up that was acquired by genomics giant Life Technologies last year. The company then created a rapid diagnostic test designed to distinguish the deadly strain–which has caused an unusual number of serious and sometimes fatal cases of kidney failure–from more common strains of E. coli. However, tests of the sprouts came back negative, possibly because the contaminated sprouts had already been thrown away.

Researchers are still studying the sequence of the bacteria for clues to its unusual virulence. Investigations for far suggest that it evolved from a strain first identified in Münster, Germany, in 2001. According to a report in the Wall Street Journal;

The 2001 strain caused fewer than five identified cases world-wide, and scientists never did identify its natural reservoir—where a new strain of the E. coli bug can originate, such as in cattle. But the genetic analysis showed that as the 2001 bug likely swapped genetic material with other bacterial strains, some big changes occurred.

The 2011 version turns out to be resistant to eight classes of antibiotics, including penicillin, streptomycin and sulfonamide. The likely reason is that rapid evolution “resulted in the gain of more genes during the last 10 years” that conferred immunity against many more antibiotics, according to BGI.

The bug’s genome has been made publicly available, so that scientists around the world can scour it for clues. Even some non-geneticists are taking a crack interpreting it.

Keep Reading

Most Popular

A Roomba recorded a woman on the toilet. How did screenshots end up on Facebook?

Robot vacuum companies say your images are safe, but a sprawling global supply chain for data from our devices creates risk.

A startup says it’s begun releasing particles into the atmosphere, in an effort to tweak the climate

Make Sunsets is already attempting to earn revenue for geoengineering, a move likely to provoke widespread criticism.

10 Breakthrough Technologies 2023

Every year, we pick the 10 technologies that matter the most right now. We look for advances that will have a big impact on our lives and break down why they matter.

These exclusive satellite images show that Saudi Arabia’s sci-fi megacity is well underway

Weirdly, any recent work on The Line doesn’t show up on Google Maps. But we got the images anyway.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.