Wednesday, January 14, 2009

Gonna Wash Those Germs Right Off Of My Hands

 

 

# 2655

 

(With apologies to Rogers and Hammerstein)

 

 

Among the most frequently touted NPI's (Non Pharmaceutical Interventions) by health officials for a pandemic is the same advice your mother gave you before dinner:

 

Go wash your hands!

 

As a former paramedic, who worked at a time before wearing latex or vinyl gloves became de rigueur, I quickly picked up the habit of washing my hands a dozen or more times each day.

 

And not just a quick wash, either. 

 

After every call you'd find me at the ER sink scrubbing maniacally up to my elbows with Betadine soap.  If you'd seen some of my patients, you'd understand why.

 

Thirty years later I've added an appropriate quantity of vinyl gloves to my prep stash, but I am still a compulsive hand washer. 

 

The fact that I ran more than 10,000 emergency ambulance calls - without wearing gloves - and never contracted any diseases from my patients, was enough to convince me of the value of handwashing.

 

But that is, as they say, anecdotal evidence.  Not scientific proof of the value of washing one's hands.   

 

Luckily, we now have a scientific study on the efficacy of handwashing.  Specifically, on how well it rids the  hands of the influenza virus.

 

Clinical Infectious Diseases 2009;48:285–291

© 2008 by the Infectious Diseases Society of America. All rights reserved.

1058-4838/2009/4803-0003$15.00

DOI: 10.1086/595845

MAJOR ARTICLE

Efficacy of Soap and Water and Alcohol-Based Hand-Rub Preparations against Live H1N1 Influenza Virus on the Hands of Human Volunteers

M. Lindsay Grayson,1,2,3 Sharmila Melvani,1 Julian Druce,4 Ian G. Barr,5 Susan A. Ballard,1 Paul D. R. Johnson,1,3,4 Tasoula Mastorakos,5 and  Christopher Birch4

1Infectious Diseases Department, Austin Health,  2Department of Epidemiology and Preventive Medicine, Monash University, 3Department of Medicine, University of Melbourne, and 4Victorian Infectious Diseases Reference Laboratory, Melbourne Health, and 5World Health Organization Collaborating Centre for Influenza, Melbourne, Australia

 

Background.  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.

 

Methods.  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 1 of 5 HH protocols (no HH [control], soap and water hand washing [SW], or use of 1 of 3 alcohol-based hand rubs [61.5% ethanol gel, 70% ethanol plus 0.5% chlorhexidine solution, or 70% isopropanol plus 0.5% chlorhexidine solution]). H1N1 concentrations were assessed 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.

 

Results.  There was an immediate reduction in culture-detectable and PCR-detectable H1N1 after brief cutaneous air drying—14 of 20 health care workers had H1N1 detected by means of culture (mean reduction, 103–4 TCID50/0.1 mL), whereas 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), with SW 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.

 

Conclusions.  HH with 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.

 

 

 

This study would seem to back up Public Health's recommendation to wash your hands frequently during a pandemic (frankly, it's an important habit to maintain all the time. Pandemic or not).

 

A good scrubbing with soap and water produced the best results, but all three alcohol gels dramatically reduced the level of viral contamination of the hands as well.

 

Those test subjects who did not wash or sanitize their hands still carried the H1N1 virus on their hands 60 minutes after the initial contamination

 

Something to remember the next time you cough or sneeze into your hands.

 

Now, how much sanitizing gel do I have stockpiled?