I once asked, sex workers to help me masturbation can cause me some STD infection. I know that 0 risk. But I want to emphasize is the wound on my scrotum at the time, was the nails scratching. I want to know, in the case of the wound, whether 0 risks of infection of sexually transmitted diseases and AIDS?Because I search the previous comments, rarely mention the wound.Please help me,thank you very much.