He has extensive experience in the diagnosis and treatment of sexually transmitted diseases, infections of the genitourinary tract, and HIV and AIDS. He has published over two hundred peer reviewed papers, is the author of a number of textbooks and has contributed to many others. For over twenty years, he was the senior consultant of the GUM Department of St Mary’s Hospital, Paddington, and was Medical Director of that hospital for seven years. His current clinical interests include the management of HPV infection and genital warts, chronic pelvic pain and bacterial prostatitis, and the complications of treatment of HIV infection and AIDS.