For years, researchers have tracked the source of hospital outbreaks back to superbug-splashing sinks. For instance, researchers found an outbreak in a Canadian hospital that spanned 2004 to 2006 was caused by multidrug-resistant Pseudomonas aeruginosa breeding and splashing out of the drains of hand-wash sinks in patient areas. Thirty-six patients were infected in the outbreak, 12 of whom died of their sink-spawned infection. Investigators found that with the water running, the sinks could launch deadly germs at least a meter away.
Despite the discoveries, researchers have puzzled over how sinks become superbug spreaders—and how to keep them from doing it. In the case of the Canadian hospital outbreak, no amount of cleaning or disinfectants fixed the problem. The hospital only ended the outbreak by renovating the sinks so they weren’t so splashy.
Now, with a new study published in Applied and Environmental Microbiology, researchers may finally have an answer to superbugs’ sink-dwelling skills: They survive in P-traps and can quickly climb pipes. More specifically, researchers at the University of Virginia found that bacteria can happily colonize a sink’s P-trap and then sneak back up the pipe and into the drain by forming a protective, creeping film, called a biofilm, on the plumbing. Once they get to the drain, they only need a burst of water to scatter up into the sink and surrounding, touchable surfaces.