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Study: Hospital Coffee Makers Not Likely Causing Bacterial Infections

coffee cup

Researchers in Germany found that public coffee machines in hospitals and hospital workers’ homes are not likely spreading bacterial infections.

After swabbing 25 machines exposed to the bare hands of users and analyzing the results, the team concluded that banning coffee machines would not be a useful measure in reducing infection in hospital settings. 

Additionally, the research team found that sharing the bacterial growth profiles with owners/operators of coffee machines resulted in the unexpected outcome of enhanced cleaning measures.

In a press release from the British Medical Journal (BMJ), the research team noted numerous other studies exploring hospital-acquired (nosocomial) infections and how they may relate to specific objects, such as doctors’ clothing or hospital bibles.

The research focused on a group of pathogens identified by the World Health Organization (WHO) as “high-priority” for their antibiotics resistance and potential for fatal outcomes.

For two months, the research team took swabs from various parts of 17 fully automatic, capsule-based and other espresso machines at a hospital in Cologne. Eight other machines from hospital staff homes were also tested. All of the coffee machines had been in use for at least a year, and no special cleaning preceded the testing.

roasted coffee

Unsurprisingly to the research team, significant microbial growth was detected on every coffee machine. Meanwhile, the public hospital coffee machines were about three times as “heavily colonized by bacteria” (360 strains isolated from 72 positive swabs) as the home machines.

Most of the detected bacteria were the kind that live in the gut or on the skin and pose no health threat. Zero antibiotic-resistant pathogens were identified, and only “a few medically relevant” pathogens were found, according to the BMJ release.

Chief among those was Staphylococcus aureus, which was found once on the buttons of a home coffee maker and once on the inside of a water tank at a hospital machine. The latter may be especially relevant to people who work on or maintain coffee machines.

“Growth inside the water tank indicates that users’ hands touch even unlikely parts of the machines,” the authors wrote.

However, the findings generally gave the thumbs up to hospital coffee makers.

“To our great relief, despite their potential for pathogen origins in nosocomial outbreaks, a general ban on coffee makers doesn’t seem necessary,” the researchers wrote.

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