Could stethoscope be a source of infection?

Objectives: We aimed to determine the prevalence of bacterial colonisation of stethoscopes in various departments in a district hospital and audited the effect of staff education at reducing this contamination.
Methodology: Bacteriological culture swabs were taken from the stethoscopes of consultants, trainees, medical students, physiotherapists and nursing staff in various departments. A campaign was launched and all the staff was asked to regularly clean the stethoscopes with alcohol wipes after each use. After an interval of one week, culture swabs were repeated and antibiotic sensitivity testing was carried out. The staff habit of cleaning their stethoscopes was compared before and after the campaign.
Results: Ninety two stethoscopes were swabbed, 47 in the first week and 45 in the second week. In the first week almost all (n=44) stethoscopes were positive for staphylococcus aureus. In the second week, 38 stethoscopes had positive cultures, all of which grew Staphylococcus epidermidis. None of the cultures were positive for methicillin resistant Staphylococcus aureus (MRSA) in either week. The number of colony forming units dropped significantly from a median of 20 (range 0-50) in the first week to a median of 8 (range 0-30) in the second week. Staff awareness led to increased frequency of stethoscopes cleaning.
Conclusion: Stethoscopes carry potential pathogens, but staff education and change in stethoscope cleaning habits reduce the risk imposed by the use of this standard piece of medical equipment.