So I've decided, from now on I'm going to answer that question with the following:
"Well..." (feels chest) "I'm still breathing..." (feels wrist) "I still have a pulse..." (looks in mirror or at hands) "And I don't have leprosy, so I guess I'm doing pretty good."
Or better yet:
* "Well, I don't have leprosy anymore, so pretty good."
* "Well, I'm no longer contagious, so pretty - ACHOO! Oh shit. Now I have to call the CDC again..."
* "Well, I don't have the Black Plague anymore, so... wait, what's this red ring-shaped mark on my arm? Oh crap..."
* "Well, I don't have the Black Plague anymore, so... *gurgle* " (vomits fake blood)
* "Well now that I've escaped from Saint Jude's Hospital for the Criminally Insane, pretty good."