The relative contribution of stethoscopes in microbial cross-transmission in comparison to the examiners hands has not been well described. Researchers from Geneva University Hospital in Switzerland endeavored to compare stethoscope versus hand contamination following a physical exam and identify predictors of stethoscope contamination.
Following a standardized physical exam using sterile gloves and a sterile stethoscope, bacterial contamination of the following regions were assessed using contact plates: stethoscope diaphragm, stethoscope tube, fingertips, thenar region, hypothenar region and back of physicians dominant hand. Total aerobic colony count (ACC) were determined on digital photographs using a counting tool.
A total of 56 patients (62 percent males; median age, 66) were recruited. Median (IQR) contamination (in ACC/25cm2) of examiners dominant hand and stethoscope were as follows: fingertips: 835 (IQR, 332-1638), stethoscope diaphragm: 173 (IQR, 36-535), stethoscope tube: 116 (IQR, 34-321), hypothenar region: 16 (IQR, 8-59), thenar region: 15 (IQR, 4-71) and dorsum of hand: 3 (IQR, 1-16). The stethoscope diaphragm and tube were significantly more contaminated than the thenar or hypothenar regions (Wilcoxon ranksum test: p<0.001). There was no difference between the level of tube and diaphragm contamination. Diaphragm contamination was strongly associated with the patients level of skin contamination (p<0.001), the patients BMI (p=0.01) and the degree of humidity of the patients skin (p<0.001).
Schneider, et al. say their results suggest that stethoscopes diaphragm and tube are significantly contaminated following a physical exam and identify predictors of heavy contamination. These findings suggest the need to decontaminate stethoscopes following each use. Their research was presented at the International Conference on Prevention & Infection Control (ICPIC) held in Geneva, Switzerland June 29-July 2, 2011.
Reference: A Schneider, C Tschopp, Y Longtin, G Renzi, A Gayet-Ageron, J Schrenzel, D Pittet. Predictors of stethoscope contamination following a standardized physical exam. Presentation at International Conference on Prevention & Infection Control (ICPIC). BMC Proceedings 2011, 5(Suppl 6):P304
Spring Into Safety: How Seasonal Deep Cleaning Strengthens Hospital Infection Control
June 13th 2025Rooted in ancient rituals of renewal, spring-cleaning has evolved from cultural tradition to a vital infection prevention strategy in modern hospitals—one that blends seasonal deep cleaning with advanced disinfection to reduce pathogens, improve air quality, and protect patients.
Unmasking Vaccine Myths: Dr Marschall Runge on Measles, Misinformation, and Public Health Solutions
May 29th 2025As measles cases climb across the US, discredited myths continue to undercut public trust in vaccines. In an exclusive interview with Infection Control Today, Michigan Medicine’s Marschall Runge, PhD, confronts misinformation head-on and explores how clinicians can counter it with science, empathy, and community engagement.
Silent Saboteurs: Managing Endotoxins for Sepsis-Free Sterilization
Invisible yet deadly, endotoxins evade traditional sterilization methods, posing significant risks during routine surgeries. Understanding and addressing their threat is critical for patient safety.