Stethoscope study overlooks bacteria on clinicians’ hands

“What’s growing on your stethoscope? (And what you can do about it),” J Fam Pract. 2009;58:404-409, is a thought-provoking article. The study seems to prove that the simultaneous washing of hands and stethoscope with an alcohol-based foam will reduce the bacterial count on the stethoscope. This leads to the question, What’s growing on our hands?

The study implies that decreasing the colony count on the stethoscope may decrease the transmission of harmful bacteria to the patient. This theory may have been strengthened if the participants’ hands had also been cultured during both the pre- and post-wash phases, along with the stethoscopes. It has been proven that handwashing decreases colony counts if the proper technique is used.¹ However, the simultaneous washing of the stethoscope and hands, as done in this study, may not be as effective as handwashing alone. If the hands remain contaminated with harmful bacteria such as MRSA, there is a likelihood that the bacteria can be retransferred to the stethoscope soon after the post-wash period.

In order for clinicians to make effective use of this line of research, these more basic questions—Do bacteria really transfer from stethoscopes to patients? And, if so, does this transfer result in clinically relevant infections?—need to be answered.

Dominic H. Mack, MD
National Center for Primary Care,
Morehouse School of Medicine, Atlanta