Hello, sex with prostitute or frequently change your sex partner increases chance of getting
HIV. but if you are taking full precautions it can save you by HIV,
STD, Syphilis, HIV transmission is only by semen, blood, stool, it doesn't transmit by air, by kissing, by hugging, else. If you got negative HIV so its good that you still safe by HIV but it is possible to get infected in future if you will not take care of protections.