Doctors should disinfect their stethoscopes after each clinical examination because they can be a major source of bacterial contamination, a new study reports.

Researchers in Geneva found that the diaphragm on the end of the stethoscope had higher bacteria levels than every part of a doctor's hand, except fingertips.

Lead investigator Dr. Didier Pittet, from the University of Geneva Hospitals, said in a statement: "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."

Similar results were found after doctors examined patients contaminated with MRSA.

The authors of the study, published in the March issue of Mayo Clinical Proceedings, say that doctors should disinfect stethoscopes after each use.

Pittet said, "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."

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