It's only that they commit the crime more often.
The article even mentions a big clue.
71% of HIV infections are in black people.
Wow!!! The small population with the highest representation of HIV infection somehow, inexplicably, gets arrested for spreading, or trying to spread it to others.
I was told that "black don't crack", but apparently they do cracks.
And while Texas doesn't have any explicit laws against intentionally spreading HIV, people have been prosecuted for it under general criminal laws. It's apparently considered assault to intentionally or recklessly infest someone.
The white girls in TV ads that are all smoochy faced with black guys these days had better get checked often!