H1N1 (Swine Flu): Efficacy of Soap and Water and Alcohol‐Based Hand-Rubs against H1N1 Influenza Virus on Human Hands
Hand Hygiene – Does it work?
We know that we are supposed to wash our hands for good health – after all, that is what our Mom always said! But where is the scientific proof? Interesting that although pandemic and avian influenza are known to be transmitted via human hands, there are minimal data regarding the effectiveness of routine hand hygiene (HH) protocols against pandemic and avian influenza.
In a study recently published in the journal “Clinical Infectious Diseases” twenty vaccinated, antibody‐positive health care workers had their hands contaminated with 1 mL of 107 tissue culture infectious dose (TCID)50/0.1 mL live human influenza A virus (H1N1; A/New Caledonia/20/99) before undertaking one of five HH protocols. The five protocols included:
• No HH [the control group]
• Soap and water hand washing [SW]
• Alcohol‐based hand rub – 61.5% ethanol gel
• Alcohol‐based hand rub – 70% ethanol plus 0.5% chlorhexidine solution
• Alcohol‐based hand rub – 70% isopropanol plus 0.5% chlorhexidine solution
The study included assessing H1N1 concentrations before and after each intervention by viral culture and real‐time reverse‐transcriptase polymerase chain reaction (PCR). The natural viability of H1N1 on hands for >60 min without HH was also assessed.
So what were the results?
There was an immediate reduction in culture‐detectable and PCR‐detectable H1N1 after brief skin air drying—
- 14 of 20 health care workers had H1N1 detected by means of culture (mean reduction, 103–4 TCID50/0.1 mL)
- 6 of 20 had no viable H1N1 recovered
- All 20 health care workers had similar changes in PCR test results.
- Marked antiviral efficacy was noted for all 4 HH protocols, on the basis of culture results (14 of 14 had no culturable H1N1) and PCR results (cycle threshold value range, 33.3–39.4)
- SW was statistically superior to all 3 alcohol‐based hand rubs, although the actual difference was only 1–100 virus copies/μL.
- There was minimal reduction in H1N1 after 60 min without HH.
The Big Aha!
The study found “hands down” that hand hygiene (HH) with soap and water (SW) or alcohol‐based hand rub is highly effective in reducing influenza A virus on human hands, although SW is the most effective intervention. Appropriate HH may be an important public health initiative to reduce pandemic and avian influenza transmission.
I don’t know about you but after reading about this study I am feeling the need to grab a bar of soap and head to the sink for a little old fashion hand washing!
M. Lindsay Grayson, Sharmila Melvani, Julian Druce, Ian G. Barr, Susan A. Ballard, Paul D. R. Johnson,Tasoula Mastorakos and Christopher Birch Infectious Diseases Department, Austin Health, Department of Epidemiology and Preventive Medicine, Monash University, Department of Medicine, University of Melbourne, and Victorian Infectious Diseases Reference Laboratory, Melbourne Health, and World Health Organization Collaborating Centre for Influenza, Melbourne, Australia