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.
We performed a multicentre, internal-crossover study comparing bacterial contamination levels in washrooms with hand-drying by either paper towels (PT) or jet air dryer (JAD, Dyson). 120 sampling sessions occurred over 12 weeks in each of 3 hospitals (UK/France/Italy). Bacteria were cultured from air, multiple surfaces and dust. Washroom footfall (patients/visitors/staff) was monitored externally.
Footfall was nine times higher in UK washrooms. Bacterial contamination was lower in PT vs JAD washrooms; contamination was similar in France/UK, but markedly lower in Italy washrooms. Total bacterial recovery was significantly greater from JAD versus PT dispenser surfaces at all sites (median 100-300vs0-10 CFU; all p<0.0001). In UK/France, significantly more bacteria were recovered from JAD washroom floors (median 24vs191 CFU, p<0.00001). UK MSSA recovery was 3x more frequent and 6-fold higher for JADs vs PTs surfaces (both p<0.0001). UK MRSA recovery was 3x more frequent (21vs7 CFU) from JAD versus PT surfaces or floors. Significantly more enterococci and 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.
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.