LONDON -- They were the final resting place for victims of the Black Death, but London’s underground medieval plague pits are now unlocking the secrets of modern-day infectious diseases.

The bodies of tens of thousands of Londoners were thrown into communal graves after one of the most devastating epidemics in human history swept through Europe in the 14th century.

Between 1348 and 1351, the Black Death -- or bubonic plague -- killed up to three in five people as it spread rapidly through pre-industrial cities, unchecked by sanitation or modern medicine. That, and subsequent waves of the Yersinia pestis bacterium, claimed the lives of tens of millions of Europeans.

WHO map: Spread of bubonic plague in Europe

Direct descendants of the same plague still exist, killing about 2,000 people each year – although they are often now treatable with antibiotics.

Earlier this month, a 7-year-old girl contracted a genetic variant of Black Death at a campground in Colorado.

The girl, who was treated for the illness in a Denver hospital, is thought to have caught the disease in the same way as her medieval ancestors - from fleas living on rodent carcasses.

Next month, a conference of forensic scientists will hear how an international team of experts - led by researchers based at McMaster University in Hamilton, Canada, and the University of Tubingen in Germany - sequenced the entire genome of the Black Death using DNA extracted from plague victims.

The team used DNA from bodies buried at pits including one at East Smithfield, now underneath the heart of central London.

It is the first time an ancient disease has been reconstructed, providing clues as to how it has evolved and whether it could strike again in future.

The scientists hope their work heralds a new era of research into infectious disease.

Additional reporting by Alastair Jamieson, NBC News

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Those baby changing stations found in public bathrooms often look a little suspect when it comes to cleanliness. But of all the things you might imagine would be mucking up the surface, probably cocaine didn’t cross your mind.

But that’s exactly what was found on 92 out of 100 nappy changing stations tested at shopping centers, hospitals, police stations and churches (!) in the UK, reported The Daily Telegraph.  A team of journalists from Real Radio conducted the investigation as part of the Cocaine Unwrapped series.

One former addict, going by the name Kerry, told the Real Radio journalists she “was taking cocaine in my dinner times in the toilets [and] I was coming back off my head.”

Last month, the UK was named the cocaine capital of Europe, with nearly 5 percent of residents saying they’ve tried it at least once, according to the European Monitoring Centre for Drugs and Drug Addiction.

While the study was done in the UK, it does give us pause when you think about what exactly happens on pull-down tables that are so convenient for changing a baby or, apparently, snorting a line.

We don’t know about you, but we plan on giving it an extra wipe down next time we use one.

Do you use diaper changing tables in public restrooms? What are your tips for protecting your baby?