Not just cold, but dirty: Stethoscopes carry more bugs than doctors' hands, a new study shows.
However, experts say not to worry.
The research, published in international clinical journal Mayo Clinic this month, found doctors' stethoscopes could spread more infectious bacteria than hand contact.
It said stethoscopes randomly sampled in healthcare settings were "almost universally" contaminated by potentially harmful microorganisms originating in hospital (called nosocomial pathogens).
Most doctors preferred to use their own stethoscope, and as doctors moved from patient to patient, their equipment could spread superbug-like bacteria, such as Methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to antibiotics.
"If hand hygiene is considered an essential infection-control measure to help prevent the spread of pathogens both in the healthcare setting and in the community, it seems only logical that measure to minimise the accumulation of potential nosocomial pathogens on stethoscopes are needed to prevent transmission to vulnerable patients," the report said.
Studies have shown that wiping the head of the instrument with antiseptic or disinfectant usually got rid of any contamination.
Josh Freeman, a clinical microbiologist at the Auckland District Health Board and clinical lead of the Hand Hygiene NZ programme, said the findings were important and applicable to New Zealand.
However, they must be considered in perspective with other infection-control issues.
"[The research] is true of shared medical equipment in general, so there's a broader issue here," Freeman said.
"There's no doubt stethoscopes can spread these bugs just the way that hands can. But the number of times stethoscopes are used in the course of a day is tiny compared to the number of times healthcare workers' hands come into contact with a patient.
"Stethoscopes are primarily used by doctors, who are a very small percentage of healthcare workers in general, and stethoscopes are only involved in a small percentage of doctor-patient contacts. So, it's a small percentage of a small percentage."
Equipment should be sterilised between patients, but there was no information available to show how often that happened, Freeman said.
Antibiotic-resistant "superbugs" were an issue of high concern in New Zealand, but not "out of control", as in other places.
Hand hygiene remained a more important measure in the fight against healthcare-associated infections, such as MRSA.
"While stethoscopes come into contact with intact skin, hands can be used to lift a dressing on a surgical wound, or to access an IV line that has direct contact with the bloodstream," Freeman said.
"That's another reason why we focus on the hands. But [shared medical equipment] is an important footnote."
Latest DHB hand hygiene performance measurements show that national hand hygiene performance has risen in the past year, from 62 per cent in October 2012, to 71 per cent in October 2013.
Freeman said any score above 70 was "pretty reasonable" given the high standard of auditing conditions, and compared favourably with international results.
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