Should Giving Someone an STD Be a Crime?

Gideon wonders whether it is good or bad for public health to prosecute an HIV-positive person for failing to disclose his HIV status before having sex with and infecting another person. I can't get away from the issue, though, of whether it is appropriate to apply the criminal laws to these cases at all. And, if we do prosecute them, why does it seem that such prosecutions are basically limited to HIV/AIDS? Read my comments to Gideon's post and post your thoughts here.