Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods

Abstract

To use a MS2 bacteriophage model to compare three hand-drying methods, paper towels (PT), a warm air dryer (WAD) and a jet air dryer (JAD), for their potential to disperse viruses and contaminate the immediate environment during use. Participants washed their gloved hands with a suspension of MS2 bacteriophage and hands were dried with one of the three hand-drying devices. The quantity of MS2 present in the areas around each device was determined using a plaque assay. Samples were collected from plates containing the indicator strain, placed at varying heights and distances and also from the air. Over a height range of 0·15-1·65 m, the JAD dispersed an average of >60 and >1300-fold more plaque-forming units (PFU) compared to the WAD and PT (P < 0·0001), respectively. The JAD dispersed an average of >20 and >190-fold more PFU in total compared to WAD and PT at all distances tested up to 3 m (P < 0·01) respectively. Air samples collected around each device 15 min after use indicated that the JAD dispersed an average of >50 and >100-fold more PFU compared to the WAD and PT (P < 0·001), respectively. Use of the JAD lead to significantly greater and further dispersal of MS2 bacteriophage from artificially contaminated hands when compared to the WAD and PT. The choice of hand-drying device should be considered carefully in areas where infection prevention concerns are paramount, such as healthcare settings and the food industry.