Determining the Presence of Bacteria on Stethoscopes: How a Pilot Study Led to a Change in Hospital Policy

Unclean medical equipment, such as stethoscopes, have been implicated in the spread of bacteria which may lead to increased nosocomial infections in the healthcare setting. This pilot study was conducted to determine if cleaning stethoscopes before patient contact decreased the transmission of bacteria. A convenience sampling of 30 stethoscopes was randomly selected from staff working in acute and medical/surgical units at a local hospital. Each stethoscope was cultured for bacterial growth within 48 hours: prior to cleaning, after cleaning with alcohol and after a one-minute standard patient assessment. The pre-cleaning culture indicated no bacteria growth (10%), scant or light normal skin flora (70%), moderate skin flora (10%) or the presence of bacteria (10%). Bacteria found on the stethoscopes included heavy gram negative rod and heavy gram positive cocci, moderate presumptive eikenella species, and light group D enterococcus. The post-cleaning culture was successful at eliminating bacterial growth – 97% had no growth and 3% had light normal skin flora. After the one-minute standard patient assessment, the majority of the stethoscopes either had no bacteria growth (30%) or had scant or light normal skin flora (60%). 7% of the stethoscopes presented with moderate normal skin flora and 3% with moderate gram negative rod. A minor percentage of stethoscopes were contaminated with bacteria that could potentially be transmitted to the patient. Given the effectiveness of alcohol cleaning to eliminate bacteria growth on stethoscopes, hospital policy was changed and now all stethoscopes need be cleaned with alcohol prior to patient use.