Roughly one in three stethoscopes carried by emergency medical service (EMS) providers harbor the superbug MRSA (methicillin-resistant Staphylococcus aureus), a small study carried out at one hospital shows.

The investigation checked 50 stethoscopes provided by EMS professionals in an emergency department.

Dr. Mark A. Merlin, from Robert Wood Johnson Medical School, New Brunswick, New Jersey, and colleagues found 16 stethoscopes were colonized with MRSA.

Sixteen of the EMS personnel could not remember the last time their stethoscope was cleaned, according to the report in the journal Prehospital Emergency Care. Typically, the time from last stethoscope cleaning to the test date was 1 to 7 days.

As might be expected, with more recent cleaning, the odds of MRSA colonization fell significantly.

"In most busy EMS systems, the concept of cleaning an entire ambulance after every patient is not practical," Merlin's team notes. "Cleaning a stethoscope, however, is not labor-intensive, does not require much time, and does not require any special equipment beyond currently stocked items."