Could a fist bump be a cleaner, better way for people to greet each other, especially in germy hospitals? British researchers have done an experiment that seems to say yes.
They tested just how many bacteria are transferred hand to hand during a handshake, a high-five and a fist bump. Handshakes are the worst, they found, while a high-five passed along half as many bacteria. Fist bumps were the cleanest greetings, David Whitworth of Britain’s Aberystwyth University found.
“Adoption of the fist bump as a greeting could substantially reduce the transmission of infectious disease between individuals,” Whitworth and colleagues report in the American Journal of Infection Control.
“Adoption of the fist bump as a greeting could substantially reduce the transmission of infectious disease between individuals."
They were looking at recommendations specifically for doctors, who are encouraged to be personal and friendly but who risk passing along sometimes dangerous germs to their patients. “Indeed, health professionals have been specifically encouraged to offer handshakes to meet patients’ expectations and to develop a rapport with them,” they wrote.
They set up an experiment to see if common wisdom holds true – that a damp, sweaty handshake transmits more germs than a quick, dry fist bump.
One experimenter put on a sterile glove, immersed it into a bath of E. coli bacteria, and allowed them to dry. Then the experimenter shook hands, did high-fives and fist bumps with colleagues wearing sterile gloves.
The sterile gloves were tested to see how many of the bacteria had gone across.
“Nearly twice as many bacteria were transferred during a handshake compared with a high five, whereas the fist bump consistently gave the lowest transmission,” the researchers wrote.
The firmer and longer the handshake, the more germs came across.
It makes sense – many studies have shown that a damp palm hosts a diverse population of bacteria and fungi. People are covered with bacteria, but the hands are notoriously good carriers.
“Whatever's on our hands, we've just exchanged.”
Many cultures value low- or no-contact greetings, such as the namaste favored in south Asia – made with folded hands and a slight bow – or the various bows employed in China and Japan. Doctors may want to consider a hands-free approach, suggests Mary Lou Manning, an infection specialist at Thomas Jefferson University in Philadelphia, who is president-elect of the Association of Professionals in Infection Control.
“Whatever's on our hands, we've just exchanged," Manning said.
Whitworth’s team doesn’t think people would go for it. “It is unlikely that a no-contact greeting could supplant the handshake; however, for the sake of improving public health we encourage further adoption of the fist bump as a simple, free, and more hygienic alternative to the handshake,” they suggested.
But Manning doesn’t even see the point of the fist bump. “Rather than replace the handshake with something else that has contact, probably the better approach to keep patients safe is really not to do it at all,” Manning said.
Instead, inclining the head or even a little bow might work, she suggested. “A namaste is becoming more common as well,” she added. "More and more people are doing yoga and becoming familiar with it."
That doesn’t mean people must abandon all friendly greetings, and some might be less germy than expected. Handshakes transmit infection because people use their hands to touch their eyes, nose and mouth. The mucous membranes are where the germs can get into the body.
"Those cheeks are not going to touch anything else."
But skin-to-skin contact away from the hands might not be bad at all. Cheek kisses may look unhygienic, Manning advises, but may actually be less likely to pass infection than even a handshake.
“I can’t even imagine it. Those cheeks are not going to touch anything else,” Manning said.
“Even though it will be a little germy on your cheek, the chances it will be transmittted anywhere are pretty remote. It’s cheek. It’s skin,” she added.
“In terms of germiness, I think the possibility of transmitting anything to anybody else is really, really, really low.”