How about instead of quarantine, we had instead tattooed all HIV sufferers across the forehead?
You could attach an unremovable (without the key) leg tag with a warning on it. This would be reversible and not on display during the normal course of daily life, diminishing the stigma.
I only have hazy memories of the 1980s, but I'm pretty sure the fashions of the day still allowed you to have sex without taking any clothes off. You'd need a very different piece of equipment to enforce this.
(I was going to improve a link to the Wikipedia article for chastity cages here, but it includes NSFW images. Investigate them at your own peril.)
A post from Gregory Cochran's and Henry Harpending's excellent blog West Hunter.
The commenter Ron Pavellas adds:
The Wasserman Test.