Bacterial contamination of stethoscopes used by health workers: public health implications

Abstract

Background: This study was designed to assess both the potential for bacterial transmission by stethoscopes used by health-care workers in Nigeria and the implications for patient safety and control of hospital-acquired infections.

Methodology:  A structured questionnaire was administered to health workers and the surface of the diaphragm of their stethoscopes swabbed for bacteriological analysis using standard techniques.

Results and Conclusions: Of the 107 stethoscopes surveyed, 84 (79%) were contaminated with bacteria; 59 (81%) of the contaminated stethoscopes belonged to physicians and 25 (74%) were from other health workers.  Isolates included Staphylococcus aureus (54%), Pseudomonas aeruginosa (19%), Enterococcus faecalis (14%), and Escherichia coli (13%). All stethoscopes that had never been cleaned were contaminated while lower levels of contamination were found on those cleaned one week or less before the survey (χ² = 22.4, P < .05).  Contamination was significantly higher on stethoscopes cleaned with only water (100%) compared to those cleaned with alcohol (49%) (χ² = 30.17, P < .05). Significantly fewer (9%) stethoscopes from health workers who washed their hands after seeing each patient were contaminated when compared with the instruments (86%) of those who did not practice hand washing (χ² = 23.79, P < .05).  E. coli showed the highest antibiotic resistance, while S. aureus showed the highest antibiotic susceptibility.   Strict adherence to stethoscope disinfection practices by health workers can minimize cross-contamination and ensure improved patient safety in hospital environments.