The COVID-19 pandemic may be the death knell of the handshake, although its deep anthropological roots may resurface after the viral storm is over.

The handshake is an ancient custom, with its origins thought to be a sign that one was unarmed in greeting another. With the suggestion that it originated with the opening tap of gloves in boxing, the fist bump is generally considered the hipper and less contagious version of the handshake.

The elbow bump has become the pandemic equivalent of touching fists, but these and other social gestures that bring people in close proximity are all being rethought as SARS-CoV-2 spreads globally.

Fist Bumps May Transmit Virus

A study using nonpathogenic bacteriophage MS2 as a viral surrogate found that handshakes and, to a lesser extent, fist bumps can be sources of transmission.1 Another study by the same clinical group found that both greetings also could transmit methicillin-resistant Staphylococcus aureus (MRSA).2 Curtis Donskey, MD, an infectious disease physician at Louis Stokes Cleveland VA Medical Center, led the research.

“In both studies, the bottom line is that any sort of greeting that involves contact between hands seemed to be very efficient at spreading viruses or MRSA,” he says. “Even though the fist bump was statistically better than the handshake, with a little bit lower transfer, there was still plenty of transfer. You definitely wouldn’t want to do a fist bump with a COVID patient.”

In the viral study, 22 participants used a keyboard and mouse contaminated with MS2 for two minutes, then shook hands and fist-bumped in randomly assigned order with 22 noncontaminated participants. “After use of the contaminated keyboard and mouse, the fist bump greeting resulted in significantly less frequent transfer of bacteriophage MS2 and in fewer viral particles transferred than the handshake,” the authors found. “However, the frequency of viral transfer with the fist bump was strikingly high despite the reduced surface area of contact involving only the back of the hand.”

The findings suggest that viral particles on the fingers and palms may be transferred rapidly to the back of the hands.

No Handshakes Is ‘New Normal’

In the other study, 50 MRSA-colonized patients participated in hand greetings with researchers wearing sterile gloves. The contact portions of the sterile glove were cultured, and the number of MRSA colony-forming units were tabulated. Again, there was a reduction in the frequency of MRSA transfer for the fist bump (16%) vs. the handshake (22%). Although less, the level of contamination with the fist bump still was a concern.

“Our data would suggest that in the setting of COVID or even MRSA, [the fist bump] is probably not a good idea,” Donskey says. “The hands are a tremendously efficient way to transfer viruses or bacteria, and even hand hygiene isn’t perfect at eliminating contamination. I think as much as possible I would avoid hand-contact greetings.” That is another “new normal” of the pandemic, but it remains to be seen whether the entrenched practice of handshakes will return.

“There is a pretty significant cultural change occurring in the community and in the healthcare setting,” he says. “[Handshaking] is kind of hard to break, but it is happening now.”

REFERENCES

  1. Jones LD, Ha W, Pinto-Herrera N, et al. Transfer of bacteriophage MS2 by handshake versus fist bump. Am J Infect Control 2020;48:727-729.
  2. Pinto-Herrera NC, Jones LD, Ha W, et al. Transfer of methicillin-resistant Staphylococcus aureus by fist bump versus handshake. Infect Control Hosp Epidemiol 2020;41:962-964.