Not comparable.
There is no environmental spread of HIV. It's a bloodborne infection.
And the infection rate after transfusion of a pint (454mL) of infected blood is 100%.
And the infection rate after transfusion of a pint (454mL) of infected blood is 100%.
Not to mention infected *infusions* by dentists, either! Remember that early case/suit??
And...now that homos can donate blood....who can blame them?