毕业握手握到手软

It’s graduation season. And some scientists got to wondering whether the folks who shake hundreds of hands while passing out diplomas run the risk of coming away with a fistful of infectious microbes, such as Staphylococcus aureus. Good news—turns out the risk of being passed a disease-causing bacterium while pressing the flesh is pretty remote. That’s according to a study in the Journal of School Nursing. [David Bishai et al, Quantifying School Officials’ Exposure to Bacterial Pathogens at Graduation Ceremonies Using Repeated Observational Measures]

The researchers swabbed the palms of 14 school officials before and after graduation. They found that before the ceremony, and even after a slathering of sanitizer, hands were home to plenty of nonharmful bacteria. On the infectious scorecard, one dean brought Staph aureus to a commencement. Two others at a different ceremony walked away with it. And one of those samples came from a left hand, which didn’t participate in any of the meeting-or-greeting. So the math says that of more than 5,000 handshakes, just one may have passed along something less welcome than a sheepskin.

So if you’re graduating this spring, feel free to shake hands. While you wonder if the last person who wore that robe had anything contagious.

—Karen Hopkin