Colds spread in two ways—through the air and by direct contact. When cold sufferers exhale, cough or sneeze, they spew virus particles into the air. The uninfected inhale them and, literally, catch the cold. “Direct contact” means transmission from the fingers to the nose. People subconsciously touch their noses several times an hour. When you have a cold, nose-touching contaminates fingers with the virus. If you touch other peoples’ hands or hard surfaces—doorknobs, telephones, etc.—you deposit a virus that can survive for hours. The uninfected pick it up on their fingertips, touch their noses, and get infected.
Here’s how to break the chain of transmission:
• If you’re sick, call in sick. Going to work, school or other activities increases risk for everyone around you. Stay home for a day or two.
• Avoid cold sufferers. If they’re family, this may be difficult. But keeping your distance reduces risk.
• Wash your hands. This prevents direct-contact transmission. At one daycare center, Purdue researchers taught children to wash their hands often to prevent colds. Children at another center received no such instruction. The hand-washing youngsters caught significantly fewer colds.
• Keep your fingers away from your nose.
• Cover your mouth. This limits the number of virus particles you release into the air. The preferable method nowadays is to cough into your elbow, not your hands.
• Use disinfectants, which kill viruses on everyday surfaces. University of Ottawa researchers contaminated counters with cold virus, then sprayed the counters with Lysol or bleach. Both treatments killed 99.7 percent of the cold viruses.
• Retire cloth hankies. Cold virus can survive several hours in them, contaminating fingers every time you use them. Switch to disposable tissues.
San Francisco health writer Michael Castleman is the author of 11 consumer health books. Visit www.mcastleman.com