As H1N1 influenza A (swine flu) spreads, keeping hands clean is one of the most important ways to prevent infection and illness. "Frequent handwashing is probably the single most effective and simplest intervention you can do to protect yourself and your family," according to Dr. Judy Daly, spokesperson for the American Society for Microbiology.
"Influenza A viruses, of which swine flu is one, are fragile viruses that can be easily destroyed through proper hygiene, including use of soap and water and alcohol-based hand sanitizers," says Daly, director of the Clinical Microbiology Laboratories, Primary Children's Medical Center, Salt Lake City.
Washing hands with soap and clean water for 20 seconds is a sensible strategy for hand hygiene in non-healthcare settings and is recommended by the Centers for Disease Control and Prevention (CDC) and other experts. If soap and clean water are not available, an alcohol-based hand sanitizer is recommended.
Research* has shown that flu viruses can survive up to 48 hours on hard, nonporous surfaces and up to 12 hours on cloth, paper, and tissues. Measurable quantities of influenza A viruses can be transferred from stainless steel surfaces to hands for up to 24 hours and from tissues to hands for up to 15 minutes. Virus can survive on hands for up to 5 minutes after transfer from environmental surfaces.
"Flu viruses most frequently enter the body when contaminated hands touch mucous membranes of the nose, eyes, and mouth. Frequent hand hygiene certainly makes this transfer less likely," says Daly.
The American Society for Microbiology has downloadable educational hand hygiene materials, including posters and brochures for children and adults, available at
*Bean, B. et al. Survival of influenza viruses on environmental surfaces. J Infect Disese. 1982 Jul;146(1):47-51.
