If you read the story, it sounds like he was told by the health office he was good to go.
IF true, can't blame the kid.
Blame goes to both partners for not protecting themselves.
Indiana's comaprative negligence statute is here.
Overview of the Indiana Negligence Law - Hensley Legal Group, PC
I could see a jury finding the woman (as compared to him) to be at least half responsible, if not more, for not insisting that a condom be used. They could find 50% each, as well. STDs are a known risk, and precautions could have been taken by her, as there is no allegation of force.
Will be interesting to see how the medical comes out. I am not sure she has legal standing to sue the medical staff.