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Wednesday, December 12, 2012

Alcohol based hand sanitizer: Good or bad?

I took a friend to the doctor today. On entering the medical office my friend immediately sanitized his hands. He rubbed both hands together for a few seconds with a squirt of an alcohol based hand sanitizer found on the counter at the reception area. I didn't follow his lead. I could see no need. My hands were, I believed, clean. A half hour before, my hands had been deep in hot, soapy dishwater.

My friend gently chastised me for not using the supplied sanitizer. He told me a story about being at a facility hard hit by the Norwalk virus and how he escaped coming down with the gastrointestinal illness by wiping his hands and arms frequently with hand sanitizer gel.

Maybe it was a good idea there and then but here and now? I wasn't convinced. He assured me that health departments promote the use of these gels and that one had to follow the guidance of the health officials. I still wasn't convinced.

The queasiness in my gut was not from a gastrointestinal illness but out of concern that sanitizer gels may be rather inefficient killers of bacteria. I was worried the wide spread use of these gels might be contributing to the development of another strain of super bugs. The result being increasing rather than decreasing the incidence of illness.

Turning to Google, I quickly learned the Norwalk virus exhibits strong resistance to alcohol-based hand sanitizer (ABHS). A full minute of contact time with 70% ethanol is required to inactive a norovirus. If an 85% ethanol gel is used, stronger than that commonly available, the contact time need only be 30 seconds.

In some studies, twenty seconds spent washing the hands with soap and water has been found to be superior to ABHS. The use of an ABHS alone may increase the risk of infection during an outbreak.

While most soaps and sanitizers are considered antibacterial, Norwalk infection is caused by a virus. With soap and water, the infectious agent is rinsed off; With an ABHS, the microbes remain on the hands and are possibly spread over a greater area of skin.

On the positive side, my friend was correct. Many health professionals do advocate the use of ABHS gels — not as a replacement for soap and water but as a supplement when soap and water are not handy.

There are three important considerations when using an ABHS:
  • Is the concentration of alcohol greater than 60%? If it isn't, go wash your hands.
  • Are you applying enough?
  • Are you using it long enough?

So, how much gel should you use and for how long? According to The New York Times, one should vigorously rub all sides of one's hands with enough gel or foam to get them wet, and rub them together until they are dry. If one's hands are dry within 10 or 15 seconds, you haven't used enough.

One last thought, some hand gels/foams contain triclosan — and to be completely honest, so do some hand soaps. Many believe triclosan is contributing to the problem of antibiotic-resistance bacteria. If you'd like to read about superbugs, use this link to a CBC article.

Other sources: Ontario Ministry of Agriculture, Food and Rural Affairs

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