PIP: A case of HIV-2 infection is described in a 35-year-old woman born in Malabo, Equatorial Guinea, who migrated to Madrid, Spain, in 1995. It was determined through questioning the woman that her only HIV-associated risk factor was unprotected heterosexual contacts in her country of origin. Her ex-husband, to whom she had been married for 18 years, was also from Equatorial Guinea and was known to have had multiple sex partners. The woman reported having had heterosexual encounters with five other partners in her native country, although less frequently than with her ex-husband. She was unaware of her sex partners' HIV serostatus and denied having had any sexual relations in Spain during her one-year current residency. The woman was in good health and presented with a CD4+ T cell count of 486 cubic millimeters. HIV-2 infection was identified using the Pepti-LAV immunoassay and Western blot. Isolation of the infecting virus was attempted by coculturing the patient's peripheral blood mononuclear cells (PBMCs) with PBMCs from an HIV-seronegative donor according to standard protocols for HIV isolation. Nested polymerase chain reaction was later conducted on some DNA from the woman's uncultured PBMCs. Phylogenetic analysis showed that the sequence data obtained clustered with the B subtype of HIV-2.