HIV transmission in men who have sex with men.
D004739:England / Q000453:epidemiology; D006069:Gonorrhea / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006716:Homosexuality; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D012002:Rectal Diseases / Q000453:epidemiology; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000453:epidemiology; D014852:Wales / Q000453:epidemiology