ABSTRACT
OBJECTIVE: To determine differences in the recontamination of stethoscope membranes after cleaning with chlorhexidine, triclosan, or alcohol. METHODS: Experimental, controlled, blinded trial to determine differences in the bacterial load on stethoscope membranes. Membranes were cultured by direct imprint after disinfection with 70% isopropyl alcohol, 1% triclosan, or 1% chlorhexidine and normal use for 4 hours. As a baseline and an immediate effect control, bacterial load of membranes without disinfection and after 1 minute of disinfection with isopropyl alcohol was determined as well. RESULTS: Three hundred seventy cultures of in-use stethoscopes were taken, 74 from each arm. In the baseline arm the median growth was 10 CFU (interquartile range [IQR], 32-42 CFU); meanwhile, in the isopropyl alcohol immediate-effect arm it was 0 CFU (IQR, 0-0 CFU). In the arms cultured after 4 hours, a median growth of 8 CFU (IQR, 1-28 CFU) in the isopropyl alcohol arm, 4 CFU (IQR, 0-17 CFU) in the triclosan arm, and 0 CFU (IQR, 0-1 CFU) in the chlorhexidine arm were seen. No significant differences were observed between the bacterial load of the chlorhexidine arm (after 4 hours of use) and that of the isopropyl alcohol arm (after 1 minute without use) (Z= 2.41; P > .05). CONCLUSIONS: Chlorhexidine can inhibit recontamination of stethoscope membranes and its use could help avoid cross-infection.
