Abstract
Electric air hand dryers (AHD) are widely used in Japanese hospitals, but the AHD collects droplets from washed hands on a tray. These droplets are blown away with a strong air stream, which is potentially dangerous if the droplets contain harmful bacteria. This study investigated if droplets are contaminated with bacteria. Droplet trays of AHD from seven male and seven female toilets were swept with sterile swabs, then cultured in blood agar at 35°C for 48 hours. Thirteen of 14 AHDs had more than 1000 CFU/mL of bacteria. Interestingly, all AHDs from male toilets contained only normal flora of the skin such as Staphylococci and Microcococci, and no gastrointestinal flora. In contrast, AHDs in female toilets contained significantly fewer colonies of Staphylococci and Microcococci, but significantly more colonies of normal gastrointestinal tract flora such as Morganella. These results may reflect insufficient hand washing before using the AHD, as well as the differences in the body parts touched by the fingers after using the toilets. Droplets spread from AHDs are potentially hazardous because of significant bacterial contamination.
