The Bangkok short-course zidovudine trial to reduce perinatal HIV transmission: Summary of findings and operational issues

Abstract

Objective To summarize key results of the Bangkok short-course oral- zidovudine perinatal HIV intervention trial and operational issues relevant for implementation in developing countries. Methods In a randomized, placebo- controlled trial, a regimen of one 300-mg zidovudine tablet taken twice daily from 36 weeks' gestation and every 3 h during labor was evaluated in HIV- infected pregnant women who agreed not to breastfeed. The infant's HIV infection status was determined by polymerase chain reaction (PCR). Operational issues of adherence, tolerance and counselling were monitored. Results Between May 1996 and December 1997, 397 women were enrolled into the trial. Median antenatal treatment was 25 days and median number of labor doses was three. Adherence was high and the study drug was well tolerated. With zidovudine, the risk of transmission was reduced by 50% (9.4% vs. 18.9%;p = 0.006). Short-course zidovudine is now being implemented in operational programs in Thailand. Conclusions Short-course oral zidovudine is safe, well-tolerated and, in the absence of breastfeeding, can reduce perinatal HIV transmission by half. This regimen can prevent a large number of perinatal HIV infections in developing countries unable to implement the AIDS Clinical Trials Group (ACTG) 076 regimen. However, successful implementation requires antenatal care, routine HIV counselling and testing, and national and local support.