Use of 90% ethanol to decontaminate stethoscopes in resource limited settings

Abstract

BackgroundIn developing countries like Nepal, 90% ethanol is cheap and is available in most hospitals. The unavailability of isopropyl alcohol (IPA) in these settings led us to compare the efficacy between 90% ethanol and isopropyl alcohol pads in reducing the bacterial contamination of diaphragm of stethoscope.MethodsA randomized blinded experimental study was carried out to determine the difference between cleaning stethoscopes with 90% ethanol and IPA. Cultures of diaphragm were taken before and after cleaning with one of the cleaning agent. Colony forming units (CFU) count and organism identification was done by a blinded investigator. CFU before and after cleaning were compared using Wilcoxon signed–rank test. Mann Whitney U test was used to compare the decrease in CFU count between the cleaning agents.ResultsAbout 30% of the stethoscopes harbored potential pathogens. Significant reduction in CFU was observed with both IPA (Wilcoxon signed–rank test, P value <0.001) and 90% ethanol (Wilcoxon signed–rank test, P value <0.001). Comparing median decrease in CFU between cleaning with IPA and with 90% ethanol, no significant difference was found (Mann Whitney U test; U = 1357, P value >0.05).ConclusionsBoth 90% ethanol and IPA are equally effective in decontaminating the diaphragm of stethoscope. Selection of agent should be done on the basis of cost and availability.

Methods of Disinfecting Stethoscopes: Systematic Review

“…Moreover, 70 studies were commentaries or full articles not in line with the aim of the study and we have excluded them after a careful examination of the abstracts and of the full texts. Finally, we detected 17 publications [3,5,6,9,11,13,[17][18][19][20][21][22][23][24][25][26][27]. Among these, we included four letters to the editor (Figure 1).…”

“…Raghubanshi et al [13] proved that both 90% ethanol and IPA are equally effective in decontaminating the diaphragm of the stethoscope. The baseline median (IQR) was 22 (7-48) CFU for IPA and 15.5 (7-31) for 90% Ethanol, the post-cleaning median (IQR) was 0 (0-0) for both.…”

“…All the chemical disinfectants proved to limit the bacterial presence on stethoscope surfaces [9,11,13,[18][19][20][21][22]. There are various formulations (liquid, gel, foam, or putty) that can be used according to preferences and availability.…”

“…Unfortunately, although these instruments are in direct contact with many patients every day, their proper disinfection is not an established practice [2,11,12]. In addition, although the importance of careful disinfection of these tools has been repeatedly suggested [3,9,11,13], their disinfection is not yet common practice. For this reason, the US Centres for Disease Control and Prevention (CDC) published medical equipment disinfection guidelines to minimize the risk of cross infections.…”

“…Additionally, a 2015 systematic review, which investigated the possible risks of infections transmitted to patients by uncleaned stethoscopes, found a mean level of contamination in excess of the French Normalization standard for cleanliness (which equates to <5 colony-forming units per cm 2 or <20 CFU per membrane) in all studies in which contamination levels were quantified [7]. All this despite, over the years, numerous studies have demonstrated the presence of microbes on the surfaces of stethoscopes, which have principally been commensal skin micro-organisms, but also potential pathogens, such as Methicillin-Sensitive Staphylococcus aureus, Methicillin-Resistant Staphylococcus aureus (MRSA), Enterococcus, Klebsiella, Acinetobacter, vancomycin-resistant enterococci, and Clostridium difficile [7,13].…”