Transmission of lymphadenopathy-associated virus/human T lymphotropic virus type III in sexual partners. Seropositivity does not predict infectivity in all cases.

To investigate transmission of lymphadenopathy-associated virus (LAV)/human T lymphotropic virus type III (HTLV-III) in long-term sexual partners, and the relationship between lymphadenopathy-associated virus seropositivity and transmission, nine couples (five heterosexual and four homosexual) at increased risk for acquired immune deficiency syndrome (AIDS) were studied. In two heterosexual couples, transmission of lymphadenopathy-associated virus from a seropositive man at increased risk to his monogamous wife occurred. In one couple, the wife of a man with hemophilia had lymphadenopathy-associated virus antibody and decreased T helper cells; in the other couple, the wife of a bisexual intravenous drug-user had AIDS. Neither woman had a recognized AIDS risk except marriage to a seropositive man at increased risk. However, study of the other couples revealed that regular sexual contact with seropositive persons over long periods did not always lead to evidence of lymphadenopathy-associated virus infection. This study suggests that presence of lymphadenopathy-associated virus antibody does not always indicate a high degree of infectivity.