Postnatal zidovudine in prevention of vertical HIV-1 transmission in a service setting

We sought to determine the efficacy of a 4-6 week coursed of zidovudine (ZD V) in a group of infants exposed to HIV-1. A retrospective chart review was conducted on HIV-1-exposed neonates identified from February 1998 to Augus t 1999. These infants received ZDV and their mothers were counselled regard ing the risks and benefits of breastfeeding. After informed consent was obt ained, the HIV-1-status of the infant was determined by RNA-PCR after I mon th of age. Thirty-three HIV-1-exposed neonates were identified; seven infan ts were excluded, five because of insufficient data and two because of mate rnal ZDV administration. In all but three, the diagnosis was suspected beca use of maternal illness, 19 of 26 mothers having either stage 3 or 4 diseas e. The transmission rate was 15.4 per cent (4 of 26). Errors in ZDV adminis tration were detected in 20 neonates of whom four were infected (p = 1; Fis cher's exact test). Antenatal diagnosis of HIV-1 status was associated with fewer medication errors in HIV-1-exposed neonates (p = 0.017, Fisher's exa ct test). It was concluded that a transmission rate of 15.4 per cent in sym ptomatic mothers suggests efficacy. Under similar circumstances, transmissi on rates varying between 37 and 67 per cent have been reported. Antenatal d iagnosis is significantly associated with compliance to the regimen. Early identification of at-risk neonates and familiarity with the regimen may imp rove the outcome.