Docs Should Wash Stethoscopes between Patients, Too
Tests for bacteria found that stethoscopes picked up more microbes from patients than did most parts of the doc's hands. Sophie Bushwick reports
By Sophie Bushwick

SUBSCRIBE TO Science Quickly
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
During a physical exam, doctors pick up a lot from their patients. Including that patient's bacteria. To keep infections from spreading, physicians try to always wash their hands between exams. But they don't always scrub their stethoscopes.
To see just how much bacteria these instruments gather, doctors examined 71 patients, using sterile stethoscopes and gloves. After each exam, researchers collected samples from the stethoscope's surface and tube, as well as four parts of the physician's gloved hands: the fingertips, backs and two locations on the palm.
The fingertips became by far the most bacterially contaminated. But the runner-up was the stethoscope's surface, which gathered more microbes than the palms or the backs of the hands. The study is in Mayo Clinic Proceedings. [Yves Longtin et al., Contamination of Stethoscopes and Physicians' Hands After a Physical Examination]
Although fingertips picked up more than five times as much bacteria as stethoscopes did, doctors reduce that contamination before seeing the next patient by cleaning their hands. According to this study's authors, stethoscopes should get the same treatment. Then the only thing to fear is the stethoscope’s icy temperature.
—Sophie Bushwick
[The above text is a transcript of this podcast.]
Subscribe to Support Independent Journalism
Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.
When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.
Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber