AFP – A study featured in the December 2023 issue of The BMJ, reveals reassuring news for healthcare workers.
Contrary to concerns, the investigation concludes that hospital coffee machines do not contribute to the spread of disease. The study suggests that implementing a general ban on these machines is unnecessary.
In the ongoing efforts to combat hospital-acquired infections, various items, such as doctors’ ties, have been scrutinised as potential breeding grounds for bacteria.
Interestingly, despite the frequent contact with numerous bare hands, the study is the first to explore the previously overlooked possibility of hospital coffee machines as sources of infection.
To address this, researchers in Germany assessed the microbial population in healthcare-associated coffee machines, with a focus on the World Health Organization’s (WHO’s) high priority “ESKAPE” pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species.
These bacteria pose an increasing threat because they are resistant to many antibiotics and can lead to fatal bloodstream or catheter-associated infections.
From October 31 to December 31, 2022, the researchers swabbed a total of 25 coffeemakers spanning the range of fully automatic, capsule and espresso machines.
Seventeen were from break rooms and offices at a university hospital’s Department of Anaesthesiology and Intensive Care Medicine, and at the Institute for Medical Microbiology, Immunology and Hygiene – both in Cologne, Germany.
A further eight were in staff members’ homes.
All coffeemakers had been in use for at least a year, and none were specially cleaned before sampling.
There was no current disease outbreak at any of the locations at the time of sampling.
Each of the coffeemakers was swabbed at five specified sites on the machine: the drip tray, the outlet, the buttons, the handle of the water tank, and the inside of the water tank.
Species were identified from cultures using spectrometry.
Typical pathogens were grouped into “medically relevant” and commensals into “atypical pathogens“ and differentiated by Gram type: positive or negative (the latter have an outer membrane that aids antibiotic resistance).
Unsurprisingly, microbial growth was detected on every coffee machine.
Hospital machines were about three times as heavily colonised (360 strains isolated from 72 positive swabs) as home machines (135 strains isolated from 34 positive swabs).
Most detected species were commensals (bacteria that live on the skin or in the gut, and pose no threat to health).
Only a few medically-relevant pathogens were identified, and none were antibiotic resistant.
Among the eight types of medically-relevant Gram-negative species detected, 81 per cent were in coffeemakers at the hospital.
These were mainly collected from drip trays, outlets and water tank handles, emphasising the need to follow hand hygiene protocols.
S aureus was the only Gram-positive disease-causing species collected: once on the buttons of a home coffeemaker and once on the inside of a water tank at the hospital.
This suggests that users’ hands touch even unlikely parts of the machines, note the authors.
“To our great relief, despite their potential for pathogen origins in nosocomial outbreaks, a general ban on coffeemakers doesn’t seem necessary,” they wrote.
What’s more, the study has reportedly resulted in extensive cleaning measures.
They added: “Our thoughts now turn to tea-drinking nations.
“Are teapots, kettles and hot water spouts similar breeding grounds for bacteria?
“Are the high temperatures in the pots sufficient to kill all potential pathogens?
“And what about the handles?”
