Pilot study suggests hospital washrooms with jet air dryers carry more germs


Further research needed to understand if different hand-drying options have an impact on potential infections in washrooms

An expert study suggests that hospital washrooms with jet air dryers may be at risk of spreading more germs than those providing single-use paper towels.

The study, funded by the European Tissue Symposium, ETS, was carried out over seven days during a three-month period by leading expert, Professor Mark Wilcox from the microbiology department at Leeds Teaching Hospitals NHS Trust and the University of Leeds.

Researchers examined the number of microbes in the air and on the surfaces in two men’s washrooms in the same hospital: one had paper hand towels to dry hands after handwashing and the other had a jet air dryer. The washrooms were used by hospital staff, patients and visitors.

Key findings included:

  • Mean number of micro-organisms recovered from air in washroom with jet air dryers was 1.6-fold higher than in washroom with paper towels
  • Microbial burdens on floors were significantly higher in washroom with jet air dryers than in that with paper towels – 2.0x10⁴ vs 3.3x 10³ cfu/mL
  • Jet air dryer casing also had significantly-higher microbes counts than the paper towel dispenser – 1.2 x 10⁵ vs 2.4 x 10 ⁴ cfu/ML
  • Enterococcus faecalis recovered from the jet air dryer unit was 3.4x 10³ cfu/mL compared with 71.4 cfu/mL on the paper towel dispenser

A range of previous studies have found that jet air and warm air hand dryers can spread microbes and viruses in a washroom environment.

Professor Wilcox said of the findings: “We found the paper towel washroom generally had fewer micro-organisms than the washroom with the jet air dryer.

The number and variety of bacteria found in the jet air dryer washroom was higher, with the floor and the dryer unit more heavily contaminated. On average the bacteria recovered from the air in the jet air dryer room was 1.6 times higher than in the paper towel washroom.”

The findings care particularly important for hospitals, where preventing and limiting the spread of infection is crucial and where patients have a lower resistance to infection.

“The key issue is whether this could expose patients and other washroom users to infection,” said Professor Wilcox.

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“We need further research to understand more about the risks of infection spreading as a result of hand-drying methods.”