What's growing on your stethoscope? (And what you can do about it).
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).


CONCLUSIONS
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.
Schroeder
Ariel
A
St. Joseph's High School, Natrona Heights, PA, USA. schroederma@upmc.edu
Schroeder
Maryellen A
MA
D'Amico
Frank
F
D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004866:Equipment Contamination / Q000517:prevention & control*; D000431:Ethanol; D006090:Gram-Negative Bacteria / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000254:growth & development; D006235:Hand Disinfection; D006801:Humans; D015203:Reproducibility of Results; D016037:Single-Blind Method; D012915:Soaps; D019023:Stethoscopes / Q000382:microbiology*
D012915:Soaps; D000431:Ethanol