(CBS) -- Though doctors may disinfect their hands to prevent spreading illness, there may be another bacteria-ridden object they have on them that doesn't get the same cleaning treatment: their stethoscopes.
A small study of 71 patients who were examined by physicians with sterile gloves and stethoscopes showed that the stethoscope's diaphragm -- the circular portion placed on the body -- was more bacteria-ridden than any area on the doctor's hands, except for the fingertips.
The researchers also discovered that the stethoscope's neck was more contaminated than the back of the physician's hands.
"By considering that stethoscopes are used repeatedly over the course of a day, come directly into contact with patients' skin, and may harbor several thousands of bacteria (including MRSA) collected during a previous physical examination, we consider them as potentially significant vectors of transmission," lead researcher Dr. Didier Pittet, director of the infection control program and World Health Organization Collaborating Centre on Patient Safety at the University of Geneva Hospitals, said in a press release. "From infection control and patient safety perspectives, the stethoscope should be regarded as an extension of the physician's hands and be disinfected after every patient contact."
The research was published on Feb. 27 in Mayo Clinic Proceedings. It was the first study to look at contamination levels on stethoscopes compared to physicians' hands.
The researchers said the work was concerning because of the very little difference between the number of bacteria found on fingertips and on the stethoscope's diaphragm. They urged doctors to disinfect the stethoscope after each use.
"If we pay attention to hand hygiene, using an alcohol swab to disinfect the stethoscope between patients should have an impact on reducing a percentage of transmission from patient to patient," Dr. Edward Septimus, a member of the on antimicrobial resistance committee of the Infectious Diseases Society of America, told MedPage Today. He was not involved in the study.
Some experts say that hygiene needs to be improved overall among medical professionals. A study on emergency medical providers showed that just 13 percent washed their hands before touching the patient. Devices are being tested that track hand washing adherence rates among hospital workers.
"The numbers are alarmingly low on the frequency of handwashing among physicians," Dr. Charles Cutler, chair of the American College of Physicians Board of Regents who was not involved in the research, told HealthDay. "We've got to get it to 100 percent between patients. Anything less than that is not good enough."
Other studies on the public have shown that only 5 percent of people are washing their hands correctly. This means, washing their hands with clean running water with soap, rubbing them together and scrubbing all parts of the hands. It also involves washing the hands for 20 seconds and drying them with a clean towel or air dryer.
Or maybe it's time to scrap the stethoscope entirely. A December commentary published in Global Heart called for an end to the long-used medical device, arguing it was obsolete because a handheld ultrasound can more effectively look in the chest.