Syphilis infection has recently resurfaced as a significant public health problem. Although there has been a tremendous amount of research on the epidemiology of syphilis, there has been limited work done to synthesize the extensive body of research and systematically estimate patterns of disease within high-risk groups in the Americas. The purpose of this systematic review and meta-analysis is to (1) summarize recent patterns of syphilis infection in North and South America among four high-risk groups (MSM, transgender women, sex workers, and incarcerated individuals) from 1980 to 2016, (2) identify and differentiate regional geographic epidemiologic characteristics, and (3) compare the epidemics of the economically developed countries of North America from the developing countries and public health systems of Latin America and the Caribbean. Primary studies reporting syphilis prevalence and/or incidence in at least one of the four high-risk groups will be identified from Medline/PubMed, Embase, Lilacs, SciELO, The Cochrane Library, Web of Science, Scopus, ProQuest, CINAHL, Clase, and Periódica, as well as “gray” literature sources (conference abstracts, country reports, etc.). Studies published from 1980 through 2016 will be included. Data will be extracted from studies meeting inclusion and exclusion criteria and a random effects meta-analysis of prevalence and incidence estimates will be conducted. Heterogeneity, risk of bias, and publication bias will be assessed. Pooled prevalence and incidence estimates will be calculated for comparisons based on geographic region, risk factors, and time period. Our systematic review and meta-analysis aims to contribute to an improved understanding of global epidemiologic patterns of syphilis infection in most-at-risk populations. Through systematic classification of the existing literature, and comparison of disease patterns across regional, temporal and socio-behavioral differences, we hope to improve public health surveillance and improve efforts to control the spread of disease across the Americas. PROSPERO CRD42016047306.

Mother-to-child transmission of HIV (MTCT) accounts for a significant proportion of new HIV infections in Peru. The purpose of this case–control study was to examine maternal and infant factors associated with MTCT in Peru from 2015 to 2016. For each biologically confirmed case infant, we randomly selected four birth year- and birth hospital-matched controls from five hospitals in Lima-Callao. Maternal and infant information were gathered from medical records. Simple conditional logistic regression was utilized to examine possible maternal and infant characteristics associated with MTCT. The rate of MTCT was 6.9% in 2015 and 2.7% in 2016. A total of 63 matched controls were identified for 18 cases. Protective factors included higher number of prenatal visits (odds ratio [OR]: 0.72; 95% confidence interval [CI]: 0.55–0.94, p = 0.012) and having more children (OR: 0.10, 95% CI: 0.01–0.79, p = 0.029). Risk factors included later maternal diagnosis (OR: 1.19; 95% CI: 1.06–1.34; p = 0.001) and greater viral load at the time of maternal diagnosis (OR: 1.05; 95% CI: 1.01–1.10; p = 0.022). Our study highlights the importance of targeting early and continued prenatal care as specific areas to target to prevent gaps in the HIV treatment cascade for pregnant HIV-infected women. These strategies can ensure early screening and initiation of antiretroviral therapy to reduce MTCT rates.