Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study

J Hosp Infect. 2018 Dec;100(4):469-475. doi: 10.1016/j.jhin.2018.07.002. Epub 2018 Jul 10.


Background: Hand hygiene is a fundamental component of infection prevention, but few studies have examined whether hand-drying method affects the risk of dissemination of potential pathogens.

Aim: To perform a multi-centre, internal-crossover study comparing bacterial contamination levels in washrooms with hand-drying by either paper towels (PT) or jet air dryer (JAD; Dyson).

Methods: A total of 120 sampling sessions occurred over 12 weeks in each of three hospitals (UK, France, Italy). Bacteria were cultured from air, multiple surfaces, and dust. Washroom footfall (patients/visitors/staff) was monitored externally.

Findings: Footfall was nine times higher in UK washrooms. Bacterial contamination was lower in PT versus JAD washrooms; contamination was similar in France and the UK, but markedly lower in Italian washrooms. Total bacterial recovery was significantly greater from JAD versus PT dispenser surfaces at all sites (median: 100-300 vs 0-10 cfu; all P < 0.0001). In the UK and France, significantly more bacteria were recovered from JAD washroom floors (median: 24 vs 191 cfu, P < 0.00001). UK meticillin-susceptible Staphylococcus aureus recovery was three times more frequent and six-fold higher for JAD vs PT surfaces (both P < 0.0001). UK meticillin-resistant S. aureus recovery was three times more frequent (21 vs 7 cfu) from JAD versus PT surfaces or floors. Significantly more enterococci and extended-spectrum β-lactamase (ESBL)-producing bacteria were recovered from UK JAD versus PT washroom floors (P < 0.0001). In France, ESBL-producing bacteria were recovered from dust twice as often during JAD versus PT use.

Conclusion: Multiple examples of significant differences in surface bacterial contamination, including by faecal and antibiotic-resistant bacteria, were observed, with higher levels in JAD versus PT washrooms. Hand-drying method affects the risk of (airborne) dissemination of bacteria in real-world settings.

Keywords: Aerosol; Hand hygiene; Transmission.

Publication types

  • Multicenter Study

MeSH terms

  • Bacteria / classification
  • Bacteria / isolation & purification*
  • Colony Count, Microbial
  • Cross-Over Studies
  • Environmental Microbiology*
  • Female
  • France
  • Hand Hygiene / methods*
  • Hospitals
  • Humans
  • Italy
  • Male
  • Toilet Facilities*
  • United Kingdom