The World Health Organization (WHO) recommends that all pregnant women receive antiretroviral therapy (ART) during pregnancy and breastfeeding ("Option B") or ideally throughout their lives regardless of clinical stage ("Option B+"). In February 2013, Zimbabwe's Ministry of Health and Child Welfare (MoHCW) declared that Zimbabwe would begin implementing Option B+ in October of 2013. This impact evaluation utilizes serial population-based, community-level surveys to comprehensively assess the prevention of mother-to-child HIV transmission strategy (PMTCT) 'Option B+' among mother-infant pairs in Zimbabwe. The investigators will assess the population-level impact of Option B+ in Zimbabwe using serial community-based cross-sectional serosurveys with data from three time points: 2012 (pre-Option A standard of care), 2014 (post-Option A / pre-Option B+), and 2017 (post Option B+ implementation) in order to monitor population-level trends in MTCT and HIV-free infant survival.
The investigators will compare outcomes among infants from 2017 to outcomes among mother-infant pairs who participated in similar surveys conducted in 2012 and 2014. These community-level data, along with in-depth facility survey data, will also allow the investigators to examine impact heterogeneity by the extent of integration of PMTCT and ART services at the facility. Together with effectiveness data from the serosurveys, facility-level resource utilization and cost data will allow assessment of Option B+ cost-effectiveness. In addition, this study will also include a population-based, community-level survey conducted in 2017 to assess retention of mothers in ART services after weaning (19-36 months postpartum). These data will allow the investigators to assess HIV-infected mothers' retention in care at the time of the survey, when most mothers will have stopped breastfeeding