Antiretroviral prophylaxis to prevent perinatal HIV transmission in St. Petersburg, Russia: too little, too late.

Background: We evaluated the influence of type and timing of prophylaxis on perinatal HIV transmission in St. Petersburg, Russia.

Methods: We linked surveillance data for 1498 HIV-infected mothers delivering from 2004 to 2007 with polymerase chain reaction data for 1159 infants to determine predictors of transmission.

Results: The overall perinatal transmission rate was 6.3% [73 of 1159, 95% confidence interval (CI) 4.9% to 7.7%]. Among the 12.8% (n = 149) of mother-infant pairs receiving full course (antenatal, intrapartum, postnatal) dual/triple antiretroviral prophylaxis, the transmission rate was 2.7%. Among the 1010 receiving less complete regimens (full course zidovudine, single-dose nevirapine, or incomplete), transmission ranged from 4.1% to 12.2%. Among the 28.9% (330) of mothers initiating antiretroviral drugs or=29 weeks (or not at all) had increased transmission odds (adjusted odds ratio: 4.9, 95% CI: 1.8 to 12.9; odds ratio: 5.1, 95% CI: 2.0 to 13.1, respectively).

Conclusions: In St. Petersburg, the potential for further reductions in perinatal transmission is evident, given low transmission among women receiving early combination prophylaxis.