If you are woried about getting an STI, probably best not to visit prostitutes. Prostitutes have sexual contact with thousands of men in their short careers, so yeah, they might carry an increased risk.
That's life. If you want to fuck prostitutes, you have to take the good with the bad. As long as you stay away from white girls that are run by black pimps, you should be OK. Blacks transmit more diseases per capita than other races, so try your best to stay away from girls who assoicate with black guys if you are overly worried about catching something.
If I find out a girl has black clients, I no longer book her. I don't want to get something from her, going forward.