High rates of transmission of subtype E human immunodeficiency virus type 1 among heterosexual couples in northern Thailand: Role of sexually transmitted diseases and immune compromise

The heterosexual transmission of subtype E human immunodeficiency virus typ e 1 (HIV-1) infection was evaluated in 467 couples in Thailand in whom the man was HIV-1 positive and the woman had no risk factors for HIV other than sex with her infected partner. At baseline, 216 (46.3%) of the 467 women w ere positive for HIV-1: 52.2% had male partners with CD4(+) lymphocyte coun ts of <200 cells/mu L, 45.9% had partners with counts of 200-499, and 39.2% had partners with counts of greater than or equal to 500. Women were twice as likely to be HIV positive if their male partners had a history of a sex ually transmitted disease (STD); however, their HIV prevalence was 29% amon g couples who had no STD history. We conclude that female partners of men i nfected with subtype E HIV-1 are at high risk of infection even when the ma n's CD4(+) cell count is relatively high. A high rate of STDs may contribut e significantly to this risk.