Did the wives or children of the victims of the infamous Tuskeegee experiment exhibit symptoms of syphillis? How coulld the government avoid treating them,as they didn’t sign any agreement to participate?
As for your second question, I have no answer. Even simple racism doesn’t properly answer it.
I doubt you’ll find an answer on the Internet. Perhaps you should consider reading one of the books on the subject, to get a fuller understanding of the slow change from the original short-term intent of the experiment to the decades-long wrong that it became.