Second generation heterosexual transmission of HIV-1 infection.

Reports of 217 HIV-1 infected persons have been investigated. Initially, 122 were described as having no identified risk of HIV infection and 95 were described as probably infected through heterosexual intercourse. The sexual partners of 34 of these 95 cases were reported as having acquired their infection heterosexually in the UK but information on the risk status of the sexual partners of the remaining 61 cases was lacking. Telephone follow-up through microbiologists and clinicians resulted in the recategorisation of 132 cases. Interviews were conducted with 22 HIV infected heterosexuals without a major risk for HIV infection, either in themselves or their sexual partners, and who had no evidence of heterosexual exposure outside the UK. Interviews confirmed the categorisation of 15 cases (9 male, 6 female) as due to second generation HIV-1 infection ie, infection acquired through heterosexual intercourse in the UK with a partner who also became infected through heterosexual intercourse. A possible chain of transmission is described involving three of these 15 cases.