人们常通过洗手来抑制细菌传播，但许多人往往忽略了洗完后使手变干的步骤，使得洗手的效果减弱。英国的一项新研究显示，选择让手变干的正确方法有利于防止手上残留的细菌传播到别处。
英国布拉德福德大学等机构的研究人员在新一期《应用微生物学杂志》上报告说，洗手是有效去除细菌的方法，但还不能消灭所有细菌，如果随后不设法让手正确变干，残留的细菌很容易在湿润环境中继续传播，因此让手变干也是一个很重要的步骤。
由于保持手部卫生的主要目的是防止细菌从手上传播到所拿的食物等物品上，研究人员专门设计了实验，以评估让手变干的各种方法对细菌传播的影响。即先请志愿者触摸生肉沾上细菌，随后洗手并采取不同方法让手变干，在这一过程的每个阶段都把手在培养皿上按一下，尔后再检测会留下多少细菌。
结果显示，在使用纸巾、借助各种“干手机”等方法中，使用纸巾擦手最为有效，在如此让手变干后，通过接触而传播到培养皿上的细菌数量减少幅度最大。
而“干手机”的效果取决于如何使用，有些“干手机”用暖空气将手烘干，常要求搓手以加快水分蒸发，还有的机器用高速气流将水吹干。研究人员发现，与洗手过程中搓手有更好的除菌效果不同，在烘干手部的过程中如果搓手，那么会将原来隐藏在皮肤深处未被洗掉的细菌带到手的表面，这样的手在干燥后接触培养皿时，会留下更多细菌。
但如果手在“干手机”中静止不动，那么手部干燥后在培养皿上留下的细菌数量与使用纸巾差不了太多。（生物谷Bioon.com）
生物谷推荐英文摘要：
Journal of Applied Microbiology DOI: 10.1111/j.1365-2672.2010.04838.x
Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers
A.M. Snelling1, T. Saville2, D. Stevens2, C.B. Beggs1
Aims: To compare an ultra-rapid hand dryer against warm air dryers, with regard to: (A) bacterial transfer after drying and (B) the impact on bacterial numbers of rubbing hands during dryer use.
Methods and Results: The Airblade? dryer (Dyson Ltd) uses two air ‘knives’ to strip water from still hands, whereas conventional dryers use warm air to evaporate moisture whilst hands are rubbed together. These approaches were compared using 14 volunteers; the Airblade? and two types of warm air dryer. In study (A), hands were contaminated by handling meat and then washed in a standardized manner. After dryer use, fingers were pressed onto foil and transfer of residual bacteria enumerated. Transfers of 0–107 CFU per five fingers were observed. For a drying time of 10 s, the Airblade? led to significantly less bacterial transfer than the other dryers (P < 0·05; range 0·0003–0·0015). When the latter were used for 30–35 s, the trend was for the Airblade to still perform better, but differences were not significant (P > 0·05, range 0·1317–0·4099). In study (B), drying was performed ± hand rubbing. Contact plates enumerated bacteria transferred from palms, fingers and fingertips before and after drying. When keeping hands still, there was no statistical difference between dryers, and reduction in the numbers released was almost as high as with paper towels. Rubbing when using the warm air dryers inhibited an overall reduction in bacterial numbers on the skin (P < 0·05).
Conclusions: Effective hand drying is important for reducing transfer of commensals or remaining contaminants to surfaces. Rubbing hands during warm air drying can counteract the reduction in bacterial numbers accrued during handwashing.
Significance and Impact of the Study: The Airblade? was superior to the warm air dryers for reducing bacterial transfer. Its short, 10 s drying time should encourage greater compliance with hand drying and thus help reduce the spread of infectious agents via hands.
