Background Studies have shown that rubbing alcohol pads on stethoscope diaphragms can reduce bacterial colonization, but alcohol pads are used infrequently used and not always available.
Methods We conducted a prospective, single-blinded study to investigate whether simultaneously scrubbing hands and stethoscope head with alcohol-based hand foam would significantly reduce bacterial counts on the stethoscope. Using their own stethoscope, participants imprinted the stethoscope head onto a chocolate agar plate, then used alcohol-based hand foam to cleanse their hands while simultaneously rubbing the stethoscope head. Once the stethoscope heads were dry, the participants imprinted their stethoscope heads onto a second plate. After 48 hours’ incubation, we determined the bacterial counts for the prewash and post-wash plates, and compared the 2.
Results We analyzed a total of 184 cultures (from 92 stethoscopes). Both the mean (28 prewash vs 3 post-wash, P=.001) and median (11 prewash vs 1 post-wash, P=.001) colony counts were significantly greater before being cleansed. Three methicillin-resistant Staphylococcus aureus (MRSA) colonies were identified in the prewash period; all were destroyed by the foam. The estimated number of hand washes needed to prevent 1 MRSA colony is 31 (95% confidence interval [CI], 18-89).
Conclusion Simultaneously using hand foam to clean hands and stethoscope heads reduces bacterial counts on stethoscopes. Further research is needed to determine whether this intervention can reduce morbidity and mortality associated with bacterial infection.
More than 160 years after a Hungarian physician introduced a protocol of strict handwashing and instrument sterilization to hospital wards,1 many clinicians still don’t wash their hands regularly or properly sterilize their medical equipment.2,3 The lack of stringent infection control, both in inpatient and office settings, is exacerbated by the rise in antibiotic-resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA), in particular, including community-acquired MRSA, accounts for infections ranging from severe skin lesions to sepsis, and an estimated 18,650 deaths annually.4,5
Waterless hand cleansers, such as alcohol-based foams and gels, improve handwashing compliance.6-8 These products are effective in reducing both bacterial and viral agents, are convenient to use, and may even be good for caregivers’ skin.9 But would they work on stethoscopes? Our study was designed to find out.
An often-neglected source of bacteria
Infection can spread from patient to patient, not only on hands, but also via fomites such as ventilators, computer keyboards, pagers, and stethoscopes.10-14 Antimicrobial stethoscope covers, including those impregnated with silver ions, do not decrease bacterial colonization; evidence suggests that their use may actually increase it.15 Studies indicate that rubbing alcohol pads on stethoscope diaphragms can reduce bacterial colonization, and it has been suggested that cleansing of stethoscopes daily may be as effective as more frequent cleaning.16 Unfortunately, many clinicians do not clean their stethoscopes on a regular basis.17 In addition, alcohol pads are not always available, and using them requires an extra step and produces waste.
An earlier study by a member of our research team (A.S., unpublished data, 2007) indicated that rubbing stethoscopes exposed to nonpathogenic Staphylococcus epidermidis with alcohol-based hand foam was comparable to using alcohol wipes in reducing bacterial counts. The primary objective of this study was to determine whether clinicians can simultaneously reduce bacteria on stethoscope heads and clean their hands with alcohol-based foam.
Methods
This study was a prospective, single-blinded, “before-and-after” trial—a design in which each participant served as his or her own control and used foam that was already available on site. The study was conducted at 1 community-based hospital and 1 satellite family health center; the study was approved by the hospital Institutional Review Board. A grant from St. Margaret’s Foundation covered the cost of the agar plates.
We began by asking the attending physicians, faculty, nurses, residents, and medical students who attended a grand rounds program to participate; we visited the satellite health facility to recruit participants, as well. We started with 93 participants, but 1 stethoscope was damaged during the study, so we ended up with 92 participants and 184 cultures.
Interventions
In the prewash, or “before” portion of the study, all participants imprinted the head of their stethoscope onto a chocolate agar plate. The clinicians then used a 62.5% ethyl alcohol-based foam to cleanse their hands, simultaneously rubbing the stethoscope head between their hands. After a brief drying time, the clinicians imprinted their stethoscope head onto a separate agar plate (the post-wash, or “after” component).
We did not tell participants how to wash their hands or for how long. We simply told them to cleanse their hands as they normally would and to rub the foam onto the stethoscope head, as well.