INTRAPARTUM MUCOSAL EXPOSURE TO HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV-1) OF INFANTS BORN TO HIV-1-INFECTED MOTHERS CORRELATES WITH MATERNAL PLASMA VIRUS BURDEN

The majority of vertical infections with human immunodeficiency virus type 1 (HIV-1) occur at or near delivery, strongly suggesting a mucosa l route of transmission. The frequency and level of intrapartum mucosa l exposure to HIV-1 of 22 infants born to infected mothers was investi gated. Maternal plasma HIV-1 RNA and CD4 cell count were measured at d elivery. Infant oropharyngeal aspirates obtained at birth were examine d for HIV-1 RNA by reverse transcription-polymerase chain reaction and qualitative nucleic acid sequence-based amplification. Nine infants ( 41%) had detectable levels of HIV-1 RNA, 3 of which were quantifiable (mean, 3000 copies/mL). This mucosal exposure to HIV-1 during delivery did not lead to infection of any infant. Cesarian delivery did not re duce mucosal exposure to HIV-1. Mucosal exposure did not correlate wit h maternal CD4 cell count but did correlate with maternal plasma virus load and was reduced by antiretroviral therapy.