BRADFORD ACADEMICS CONFIRM NEW DYSON HAND DRIER AS 'MOST HYGIENIC'
  
  
Research by academics in Bradford has helped rubber-stamp a new revolutionary type of hand drier as the most hygienic on the market.  
  
Professor Clive Beggs and Dr Anna Snelling of the Bradford Infection Group at the University of Bradford have been working with Dyson Ltd on the development and testing of a hygienically superior hand drier, the Dyson Airblade™.  
  
This machine, which was launched by Dyson Ltd today (Tuesday 3 October 2006) dries hand efficiently in just 10 seconds, whereas conventional warm air driers take in excess of 30 seconds to achieve a similar result.  
  
Because of its superior hand drying qualities, Professor Beggs and Dr Snelling believe that the Dyson Airblade™ drier is hygienically superior to conventional warm air driers and that it has the potential to greatly improve hand drying compliance and reduce the spread of infections.
  
Clive Beggs, Professor of Medical Technology within the University of Bradford 's School of Engineering , Design and Technology, said: "We all know that washing your hands helps to prevent the spread of infection. However, what many of us don't realise is that the hand drying process can be as important as hand washing itself. Washing with soap and water doesn't always remove all the contaminating bugs from your hands. Transfer of bacteria, including types that might be harmful, is more likely to occur from skin that is wet than from skin that is dry."
  
Prof Beggs and Dr Snelling have been responsible for the design and supervision of the microbiological trials used to evaluate the hygiene performance of the Dyson Airblade™ drier. Through a series of rigorous scientific trials, they have demonstrated the hygienic qualities of the new Dyson Airblade™ drier, which they believe has the potential to greatly improve hand drying compliance and reduce the spread of infection.
  
Dr Anna Snelling, Senior Lecturer in Microbiology within the University's School of Life Sciences , said: "Unlike hand washing, which is recognised as being a key factor in controlling the spread of infectious disease, the important role of hand drying in the overall hygiene process has remained largely unrecognised.  
  
"In reality, the drying process is as important as hand washing itself, because it has been shown that transmission of microbes is more likely to occur from wet skin than from dry skin.  
  
"Through effective drying of hands, it is possible to reduce the numbers of bacteria transferring to skin, food or other inert surfaces by around 99 per cent."  
  
Conventional warm air machines dry hands slowly, with most driers taking in excess of 30 seconds to fully dry hands. Consequently, users of such machines frequently leave before their hands are fully dry, with the result that there is increased risk of bacterial transfer to sterile surfaces touched by damp hands.  
  
Observations made by Professor Beggs and Dr Snelling (in conjunction with Dyson Ltd) revealed that men typically spend on average 20 seconds at a warm air hand drier, whilst women spend just 16 seconds. It was observed that 37 per cent of women spent no more than 10 seconds attempting to dry their hands, with only 9 per cent of women prepared to spend 30 seconds or more at the driers. It is therefore the case that most users of conventional warm air driers leave the drying process with their hands still wet or damp. This is a profoundly unhygienic practice, which is likely to lead to increased carriage of pathogenic microorganisms on the hands of individuals leaving washrooms.
  
The Dyson Airblade™ machine is a new and novel technology which is radically different from the conventional warm air hand driers commonly found in wash rooms. Unlike conventional driers which rely on evaporation and the rubbing of hands to produce a drying effect, the Dyson Airblade™ machine utilises a double air knife to strip and evaporate water from hands.  
  
In addition, the air delivered to the hands is filtered and thus sterile. It is a particularly fast and efficient process which takes only 10 seconds to completely dry hands. It therefore ensures that the hands of users are dry when they leave the machine, thus eliminating the unhygienic consequences described above, which are associated with conventional warm air driers.  
  
Unlike conventional air driers, the Dyson Airblade™ machine does not require any rubbing of hands, with the result that there is no risk of repopulating the surface of the skin with commensal bacteria from deep within the pores or under the fingernails.
  
In a rigorous microbiological trial, comparing the Dyson Airblade™ machine with other conventional warm air driers, Professor Beggs and Dr Snelling found that with a standard drying time of 10 seconds, the Dyson Airblade™ unit performed considerably better than all the other machines tested, with results which were statistically significant.  
  
The hands of fourteen volunteers were tested after they had been handling raw meat and had washed with soap and water. It was found that bacterial carriage after using the Dyson Airblade™ machine was only about 7 per cent of that resulting from use of the conventional driers. This performance, together with the very short drying time, has lead the researchers to conclude that the new Dyson Airblade™ unit has great potential to increase hand drying compliance plus efficacy, and that this may yield positive health benefits in the fight against the spread of infectious agents by the hand-borne route.
  
  
NOTES 
  
Technical background notes and research references
  
Good hand hygiene is recognised as being a key factor in controlling the spread of infectious disease and antibiotic-resistant bacteria both in hospitals and in the community, with numerous studies reporting the beneficial effects of improved hand washing (Larson 1988; Boyce et al., 2002; Jumaa 2005, Luby et al., 2005). However, while hand washing and antibacterial soaps have received much attention, comparatively little research has been done to quantify the contribution of hand drying to the overall effectiveness of the washing regime. Consequently, there is little understanding of the importance of hand drying in preventing the spread of infection.
  
It is generally accepted that the transmission of microbes is more likely to occur from wet skin than dry skin (Gould 1994; Merry et al., 2001). This occurs not only because of the physical aspects of moisture droplet transfer between one surface and another, but also because the bacteria may be in a physiological state that makes them better able to colonise new environments.  
  
Patrick et al., (1997) found that by drying the hands, the numbers of bacteria transferring to samples of skin, food or utilities, was reduced by the order of 99%. If hands repeatedly remain damp because of ineffective hand drying, it can lead to skin excoriation which in turn can lead to altered and higher populations of bacteria colonising the skin. This has been found to be a particular problem amongst certain cohorts of nurses, where their routine duties require multiple instances of hand washing per hour. This can lead to greater carriage of pathogenic Gram-negative bacteria and yeasts.  
  
More worryingly, Staphylococcus aureus can also become established as part of the normal skin flora (Larson et al., 1998). Hand drying to decrease microbial counts at the skin surface is now recognised as an essential part of hand hygiene aimed at reducing the spread of methicillin resistant Staphylococcus aureus (MRSA) in hospitals (Collins and Hampton 2005).  
  
Redway and Knight (Redway & Knight. 1998) found that for warm air driers the average man spent 20 seconds drying their hands in the air stream, while the average woman spent 25 seconds. By comparison Patrick et al. (Patrick et al. 1997) found that the average time for men using warm air driers was 17 seconds, while that for the average woman was only 13.3 seconds.  
  
In a 2006 observational study (Beggs & Snelling in conjunction with Dyson Ltd.) that took place in the washrooms of a motorway service station, men used the warm air driers for an average of 20 seconds, whilst women used them for just 16 seconds. Interestingly, it was observed that 37% of women spent no more than 10 seconds attempting to dry their hands, while only 9% of women were prepared to spend 30 seconds or more at the dryers.
  
Hand rubbing during the drying process re-populates the skin with commensal bacteria (Yamamoto et al. 2005). Consequently if hand rubbing is involved, the bacterial counts on hands will frequently be higher after the washing/drying process than before it. This is because the rubbing process tends to draw out to the skins surface commensal bacteria from deep inside the pores and under the fingernails. Consequently, the rubbing of hands when using a conventional warm air drier will contribute both to the bacterial load on the surface of the skin and possible subsequent transfer of bacteria from the hands to other surfaces.  
  
  
References
  
Boyce JM, Pittet D: Guideline for Hand Hygiene in Health-Care Settings: recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force. Infect.Control Hosp.Epidemiol. 2002, 23:S3-40.
  
Collins F, Hampton S: Hand-washing and methicillin-resistant Staphylococcus aureus. Br J Nurs. 2005, 14:703-707.
  
Gould D. The significance of hand-drying in the prevention of infection. Nursing Times. 1994; 47; 33-35
  
Jumaa PA: Hand hygiene: simple and complex. Int J Infect Dis 2005, 9:3-14.
  
Larson E: A causal link between handwashing and risk of infection? Examination of the evidence.  Infect Control 1988, 9:28-36.
  
Larson EL, Hughes CA , Pyrek JD, Sparks SM, Cagatay EU, Bartkus JM: Changes in bacterial flora associated with skin damage on hands of health care personnel. Am.J.Infect.Control 1998, 26:513-521.
  
Luby SP, Agboatwalla M, Feikin DR , Painter J, Billhimer W, Altaf A, Hoekstra RM: Effect of handwashing on child health: a randomised controlled trial. Lancet 2005, 366:225-233.
  
Merry AF, et al. Touch contamination levels during anaesthetic procedures and their relationship to hand hygiene procedures: a clinical audit. British Journal of Anaesthesia. 2001; 87; 291-294
  
Patrick DR, Findon G, Miller TE. Residual moisture determines the level of touch-contact-associated bacterial transfer following hand washing. Epidemiology and Infection. 1997; 119; 319-325
  
Redway K, Knights B. Hand Drying: a study of the hygiene and efficiency of different hand drying methods. University of Westminster , Report for The Association of Makers of Soft Tissue papers. October 1998.
  
Yamamoto Y, Ugai K, Takahashi Y: Efficiency of hand drying for removing bacteria from washed hands: comparison of paper towel drying with warm air drying. Infect Control Hosp.Epidemiol. 2005, 26:316-320.
  

(4/10/06)