Influenza spreads by some combination of airborne particles containing viruses (e.g., from infected people sneezing) and surface contamination. The relative imp

Influenza spreads by some combination of airborne particles containing viruses (e.g., from infected people sneezing) and surface contamination. The relative importance of each is unknown, and there's actually not much in the way of research indicating that hand washing helps appreciably (it's rather difficult to measure). That said, it can't really hurt, either, and may help avoid opportunistic infections joining the fray in someone who does get the flu. So it's not surprising that organizations advising the general public would tell people to wash their hands, evidence or no.