Stethoscopes are loaded with diverse bacteria, including some that can cause health care–associated infections (Infect Control Hosp Epidemiol 2018;18:1-7).
The research also found that various cleaning methods were not effective at sanitizing stethoscopes.
“This study underscores the importance of adhering to rigorous infection control procedures, including fully adhering to CDC-recommended decontamination procedures between patients, or using single-patient-use stethoscopes kept in each patient’s room,” said Ronald Collman, MD, a professor of medicine, pulmonary, allergy and critical care at the University of Pennsylvania Perelman School of Medicine, in Philadelphia, and senior author of the study.
The analysis showed all 40 of the stethoscopes in use in the ICU were significantly contaminated with a rich and diverse community of bacteria, including those related to common health care–associated infections, although it could not determine whether the stethoscopes ever made patients ill. Staphylococcus was found in abundance on all stethoscopes, with more than half of them having confirmed contamination with Staphylococcus aureus. Other bacteria that can cause health care–associated infections, such as Pseudomonas and Acinetobacter, also were widely present on stethoscopes, although in small quantities.
To assess the impact of cleaning on contamination, researchers sampled 10 additional practitioner stethoscopes before and after cleaning for 60 seconds using a hydrogen peroxide wipe, and 20 more practitioner stethoscopes before and after cleaning by the practitioners according to their usual method, which included use of alcohol swabs, hydrogen peroxide wipes or bleach wipes used for different durations. All cleaning methods reduced the amount of bacteria but failed to bring contamination consistently to the level of clean, new stethoscopes. The standardized cleaning method reduced bacteria on half of the stethoscopes to the clean level, while only 10%, or two of the 20, reached that level when cleaned by the practitioner-preferred method, leaving stethoscopes as a potential vehicle for transmission of infection.
Future research also should use similar molecular approaches to identify improved cleaning methods, study bacteria present on other “noncritical” medical devices used on multiple patients, as well as in the health care environment, and should focus on antibiotic-resistant bacteria, Dr. Collman said.