Prenatal Transmission of Syphilis and Human Immunodeficiency Virus in Brazil: Achieving Regional Targets for Elimination

Mother-to-child transmission (MTCT) of syphilis and human immunodeficiency virus (HIV) remains a significant public health concern in Latin America and the Caribbean (LAC). Despite effective interventions to prevent vertical transmission, each year an estimated 250 000 children are born in LAC with congenital syphilis (CS) and another 4700 are born with HIV [1, 2]. It has been shown that investments in preventing MTCT (PMTCT) of syphilis and HIV are very cost-effective and will avert morbidity and mortality among children [3, 4]. In 2013, an estimated 74% of pregnant women in LAC received HIV testing, with similar syphilis testing rates [5]. There are many steps along a “cascade” of antenatal services at which patients are lost from care, including access to antenatal care (ANC), HIV and syphilis testing and test result return, access to medications for PMTCT, infant diagnosis, and retention in treatment [6]. Among the countries of LAC, Brazil carries a significant proportion of the HIV and syphilis burden, yet it also has highly developed systems of PMTCT services and clinical data collection [7, 8]. The provision of free HIV care since 1996 has helped to develop HIV and syphilis ANC services [9], which, coupled with Brazil′s geographical and economic diversity, positions the country and its regions to serve as a model for many other LAC countries [10]. Although HIV control has improved over time, CS remains a substantial problem in Brazil [11, 12]. National ministries of health in the LAC region and the Pan American Health Organization (PAHO) have declared a goal to eliminate HIV and syphilis MTCT by 2015, with a plan to integrate antenatal HIV and syphilis care [13]. In particular, these goals include the following: reducing MTCT of HIV incidence to ≤0.30 cases/1000 live births (LB), reducing risk of HIV MTCT to ≤2.0%, and reducing the incidence of CS to ≤0.50 cases/1000 LB [14]. The operational requirements needed to achieve these goals are generally understood, but more insight is needed to investigate the impact they may have on PMTCT at the regional and national level. We expanded a computer simulation model of PMTCT in HIV [15–17] to include syphilis MTCT, and we populated the model with input data specific to Brazil. We used this model (1) to project the number of neonatal HIV and syphilis cases associated with current antenatal services in Brazil and (2) to project the impact of expanding syphilis- and HIV-related services in ANC.