Active maternal herpes simplex virus type 2 (HSV-2) infection increases the risk of mother-child transmission of HIV infection during childbirth, according to a report in the February issue of Obstetrics & Gynecology.
"Our results suggest treating or preventing genital ulcers during pregnancy in HIV-1 infected women may reduce the risk of mother-to-child transmission of HIV-1," Dr. Alison L. Drake from the University of Washington, Seattle, told Reuters Health.
Dr. Drake and associates investigated whether HSV-2 seropositivity at 32 weeks of gestation, cervical HSV DNA shedding at delivery, and genital ulcers at 32 weeks of gestation were associated with the risk of intrapartum HIV transmission in a nested case-control study involving 175 HIV-infected mothers in Kenya.
The presence of genital ulcers (but not antibody to HSV-2) at 32 weeks of gestation was associated with a significantly increased risk of intrapartum transmission of HIV, the team reports.
Higher maternal plasma HIV RNA at delivery, higher maternal cervical HIV RNA level at delivery, and maternal CD4 T cell counts below 200 cells/microliter were also associated with an increased risk of intrapartum transmission, the researchers note, as was delivery by cesarean section (mostly emergent cesarean section after rupture of membranes).
In multivariable logistic regression models, the presence of genital ulcers was associated with a 5.1-fold increased risk of intrapartum transmission. This risk diminished somewhat (to 4.6-fold) after adjusting for maternal CD4 T cell count below 200 cells/microliter.
"Intervention trials are needed," Dr. Drake said, "to determine the effect of HSV suppression on mother-to-child transmission of HIV-1 at the population level."
Obstet Gynecol 2007;109:403-409.
