Last fall, not long after the bloom of news about the “Indian superbug” NDM-1 — a newly identified enzyme that renders common gut bacteria indifferent to almost all antibiotics — I spoke to one of its lead researchers, Timothy Walsh of the University of Cardiff, about next steps in their research.

His work and his collaborators’ had demonstrated that many of the people infected with or carrying bacteria that incorporated the gene had undergone medical treatment in India and Pakistan, sometimes for elective surgery such as medical tourism, sometimes because they had been injured or ill while traveling. But not all, he said — and that was making them wonder whether the spread of NDM-1 had an environmental component. It was a plausible hypothesis given the apparent concentration of NDM-1 in India, a country whose sanitation systems have not kept up with its booming population. A recent UN report estimated that almost half of India’s residents — that would be up to 650 million people — lack treated drinking water and modern toilets. If you sat down to design a system to facilitate the spread of an enzyme carried by bacteria in the gut — that is, in feces — you couldn’t do better than what India already has.

“There has been very little work done or analysis done on the effect that (poor sanitation) would have on the spread of resistance and on carriage of NDM-1 within a normal population,” Walsh told me at the time. “There’s no water sampling for fecal flora or antibiotic-resistant flora.”

Well, now there is: Walsh and his collaborators have done it. And the news, as they suspected, is bad. [Read more…]