Fomites　can　transmit　some　infectious　diseases.　Human　touch　behaviors　are　known　to　affect　virus　transmission　in　buildings.　Using　video　cameras　in　a　graduate　student　office,　we　collected　more　than　98,000　touch　actions　from　14　h　of　high-resolution　video　data　of　surfaces　touched　by　fingers,　palms,　and　backs　of　hands.　Based　on　the　collected　data,　we　simulated　infection　spread　via　the　fomite　route.　90%　of　touches　to　mucous　membranes　are　by　fingers　(70%　by　fingers　of　the　nondominant　hand;　20%　by　fingers　of　the　dominant　hand).　3%　of　the　virus　released　into　the　atmosphere　by　those　infected　was　transmitted　to　other　students＇　hands,　personal-use　surfaces,　and　public　surfaces.　Public　surfaces　are　responsible　for　53%　of　virus　transmission　due　to　surface　touch　to　susceptible　students.　65%　of　the　virus　transmitted　to　the　mucous　membranes,　is　by　nondominant　hands.　93%　of　virus　intake　via　mucous　membranes　of　the　susceptible　was　from　fingers.　Door　handles　and　mobile　phones　transferred　the　most　viral　loads　to　hands　of　the　susceptible.　Total　virus　exposure　due　to　touching　has　no　significant　relationship　with　the　duration　of　being　indoors,　but　human　behavior　does.　Behavior-related　intervention　strategies　are　much　more　efficient　than　other　strategies　such　as　public　surface　disinfection.　If　we　never　touch　other＇s　personal　surfaces,　we　would　reduce　our　exposure　to　the　virus　by　80%.