I searched for information about hepatitis c and cannot understand this-dried blood is contagious for up to 4 days if it enters your bloodstream. I can't imagine how can dried blood enters someone's bloodstream-for example is dried blood on clothes a realistic risk(if touching the place with recently bled wound)...or some dried particles should somehow enter the wound? I know that people should be very careful with these kind of things but isn't it a little bit of panic that some websites suggest that even very tine traces of dried blood can infect you?
I think you raise an important issue. Researchers have uncovered many interesting findings about the survival of HCV in needles, in dried blood, etc...I think it is important from a harm reduction viewpoint to tell an addict that ANY used needle - even one with dried blood - may be harmful...But for the general public, I don't think this information is helpful because of the exact issues you point out.