Physicians' stethoscopes are teeming with bacteria

Researchers have found that although it's believed that healthcare workers' hands are the main source of bacterial transmission in hospitals it may be physicians' stethoscopes who are culprit.

Lead investigator Didier Pittet, MD, MS, Director of the Infection Control Program and WHO Collaborating Centre on Patient Safety, University of Geneva Hospitals, said that 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.

He said that 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.

In this study, 71 patients were examined by one of three physicians using sterile gloves and a sterile stethoscope. After they completed the examination, two parts of the stethoscope (the tube and diaphragm) and four regions of the physician's hands (back, fingertips, and thenar and hypothenar eminences) were measured for the total number of bacteria present.

The stethoscope's diaphragm was more contaminated than all regions of the physician's hand except the fingertips. Further, the tube of the stethoscope was more heavily contaminated than the back of the physician's hand. Similar results were observed when contamination was due to methicillin-resistant S.aureus (MRSA) after examining MRSA-colonized patients.

The results has been published in the Mayo Clinic Proceedings.