ATLANTA, Georgia (CNN) -- This week while you're traveling, if
you happen to spot a man applying hand sanitizer as he gets off
an escalator, there's a good chance it's Dr. Mark Gendreau, a
senior staff physician at the Lahey Clinic in Burlington,
Massachusetts. Travel season can be a germ fest. Make sure to
keep your hands clean. Gendreau studies germiness while
traveling, and he knows just how infectious travel can be. "The
risk of contracting a contagious illness is heightened when we
travel within any enclosed space, especially during the winter
months, when most of the respiratory viruses thrive," Gendreau
said. Studies show that germs can travel easily on an airplane,
where people are packed together like sardines. For example, a
woman on a 1994 flight from Chicago to Honolulu transmitted
drug-resistant tuberculosis to at least six of her fellow
passengers, according to a New England Journal of Medicine
study. In 2003, 22 people came down with SARS, or severe acute
respiratory syndrome, from a single fel