Unlinked anonymous HIV testing.
D015492:AIDS Serodiagnosis; D000293:Adolescent; D000328:Adult; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D016036:Seroepidemiologic Studies; D014852:Wales / Q000453:epidemiology