If you want to lower your odds of getting the flu — which has sickened more than 20 million US residents since last October, according to estimates from the CDC — work on improving your hand-washing technique, the Washington Post reports.

Scrub your hands for at least 20 seconds, using soap and clean water, either warm or cold. No watch or tech-device timer handy? Just hum the song “Happy Birthday to You” twice, from start to finish. Be sure to wash your fingertips, between your fingers and under your nails — not just the palm and back of your hands. Then rinse and dry.

Sounds simple, but 2013 research from the Journal of Environmental Health notes that only 5% of people wash their hands the right way — and for long enough — to kill the germs and bacteria that reside on hands. That data came from researchers who watched more than 3,700 people at the sinks in public restrooms.

Over the years, various studies have found that, at any given moment, hundreds (if not thousands) of germs populate people’s hands. including E. coli. People touch something that has germs on it — a doorknob or a handrail, for instance — and then touch their eyes, nose or mouth before washing their hands.

Get the full story at www.washingtonpost.com