Thorough hand washing with soap and running water is a more proven method of preventing the transmission of the norovirus than alcohol-based and other hand sanitizing methods, according to the Centers for Disease Control and Prevention. The CDC notes that long-term care facilities, nursing homes and hospitals are the most commonly reported settings of a norovirus outbreak in the U.S. Outbreaks can last longer in these places and be more severe than outbreaks among otherwise healthy populations.
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6003a1.htm?s_cid=rr6003a1_w