【事实】HBV does not cross the skin or the mucous membrane barrier.
Some break in this barrier, which can be minimal and insignificant, is
required for transmission.(WHO 2002年的manual)
HBV is stable on environmental surfaces for at least 7 days, and
indirect inoculation of HBV can occur via inanimate objects like
toothbrushes, baby bottles, toys, razors, eating utensils, hospital
equipment and other objects, by contact with mucous membranes or open
skin breaks.
HBV is able to remain on any surface it comes into contact with
for about a week, e.g. table-tops, razor blades, blood stains, without
losing infectivity.