RESUMEN
OBJECTIVE: To assess the practicality and effectiveness of an Ultra-Short zidovudine regimen for prevention of perinatal HIV transmission in rural Zimbabwe. DESIGN: Double-blinded placebo-controlled randomized clinical trial. SETTING: The Salvation Army Howard Hospital, a district hospital in rural Zimbabwe. SUBJECTS: 222 HIV positive pregnant women presenting for antenatal care prior to 36 weeks were randomized. Twenty nine women were lost to follow up. INTERVENTION: In the Thai regimen, mothers received zidovudine (300 mg po bid) from 36 weeks gestation until labour, and zidovudine (300 mg po q3h) during labour, and the neonates received a placebo. In the Ultra-Short regimen, the mothers received a placebo from 36 weeks to labour, then zidovudine (300 mg po q3h) in labour. The neonates received zidovudine (2 mg/kg po qid) for the first three days of life. MAIN OUTCOME MEASURE: Infant HIV RNA status at six weeks of life. RESULTS: Results were available for 90 infants from the Thai group and 89 infants from the Ultra-Short group. Infant HIV seroconversion rates at six weeks of life were 18.9% (95%CI 10.8 to 27.0) with the Thai regimen, and 15.7% [95% Confidence Interval (CI) 8.1 to 23.4] with the Ultra-Short regimen. The upper bound of seroconversion in the Ultra-Short group was lower than the 25% seroconversion boundary that was specified to show equivalence. CONCLUSIONS: Although the Ultra-Short regimen has equivalent efficacy to the Thai regimen, it also has many practical advantages. Ultra-Short is thus a preferable protocol.