The following is a short excerpt from Martin Luther's "Whether One May Flee from a Deadly Plague." Think of this in terms of the AIDS epidemic, which is less contagious than the plague in Luther's day.
This I know, that if it were Christ or his mother who were laid low by illness, everybody would be so solicitous and would gladly become a servant or helper. Everyone would want to be bold and fearless; nobody would flee but everyone would come running. And yet they don’t hear what Christ himself says, ‘As you did to one of the least, you did it to me….’ If you wish to serve Christ and to wait on him, very well, you have your sick neighbor close at hand. Go to him and serve him, and you will surely find Christ in him, not outwardly but in his word. If you do not wish or care to serve your neighbor you can be sure that if Christ lay there instead you would not do so either and would let him lie there. Those are nothing but illusions on your part which puff you up with vain pride, namely, that you would really serve Christ if he were there in person. Those are nothing but lies; whoever wants to serve Christ in person would surely serve his neighbor as well.