Abstract
BACKGROUND: Lifelong antiretroviral therapy (ART) is now recommended for all human immunodeficiency virus (HIV)-infected pregnant and breastfeeding women; however, few have described overall infant outcomes in this new era for the prevention of mother-to-child HIV transmission (PMTCT). METHODS: As part of an assessment of PMTCT program impact, we enrolled a prospective cohort study in 4 predominantly rural districts in Zambia. HIV-infected mothers and their newborns (≤30 days old) were recruited and followed at 6 weeks, 6 months and 12 months postpartum; infant specimens were tested via HIV DNA polymerase chain reaction. In Kaplan-Meier analyses, we estimated overall infant HIV-free survival and then stratified by district, community and maternal ART use. We investigated the relationship between community-level 12-month, self-reported maternal ART use and infant HIV-free survival via linear regression. RESULTS: From June 2014 to November 2015, we enrolled 827 mother-infant pairs in 33 communities. At 12 months, small proportions of infants had died (2.8%), were HIV-infected (3.0%) or were lost to follow-up (4.3%). Overall, infant HIV-free survival was 99.0% [95% confidence interval (CI): 98.0%-99.5%] at 6 weeks, 97.5% (95% CI: 96.1%-98.4%) at 6 months and 96.3% (95% CI: 94.8%-97.4%) at 12 months. Women reporting ART use at enrollment had higher infant HIV-free survival than those who did not (97.4% vs. 89.0%, P = 0.01). Differences were noted at the district and site levels (P = 0.01). In community-level analysis, no relationship was observed between 12-month infant HIV-free survival and self-reported maternal ART use (P = 0.65). CONCLUSION: Although encouraging, these findings highlight the need for rigorous monitoring and evaluation of PMTCT services at the population level.