(HealthDay News) — Stethoscopes get contaminated after a single physical exam, with the contamination greater than that seen on most of the physician’s dominant hand, barring the fingertips, according to a study published online February 27 in the Mayo Clinic Proceedings.
Yves Longtin, MD, from the University of Geneva, and colleagues compared the contamination level of physicians’ hands and stethoscopes after a standardized physical examination of 83 inpatients. After each examination, four regions of the physician’s gloved or ungloved dominant hand and two sections of the stethoscopes were sampled by pressing onto selective and nonselective media, with 489 surfaces sampled overall.
The researchers found that the median total aerobic colony counts (ACCs) were 467 for fingertips, 37 for thenar eminence, 34 for hypothenar eminence, eight for hand dorsum, 89 for stethoscope diaphragm, and 18 for stethoscope tube. The contamination level of the diaphragm was higher than that of the thenar eminence (P=0.004), but lower than that of the fingertips (P<0.001). The total methicillin-resistant Staphylococcus aureus (MRSA) contamination level was higher for the diaphragm than the thenar eminence (P=0.004). For both total ACCs and MRSA colony forming unit (CFU) counts, there was a correlation between the contamination level of the diaphragm and that of the fingertips (both P<0.001). Similarly, for ACCs and MRSA CFU counts, contamination of the stethoscope tube increased with increasing contamination of the fingertips (both P<0.001).
“Our findings provide strong evidence of the potential for stethoscope-mediated transmission of microorganisms and the need to systematically disinfect stethoscopes after each use,” the authors write.