Impact of Congenital Syphilis and zika virus Infections on Neonatal Outcomes in a Context of Social Vulnerability: An Ecological Study

Abstract

Objective: tto analyze the impact of congenital syphilis and Zika virus infection on neonatal outcomes in Brazil, considering the context of social vulnerability. Methods: this is an observational, ecological, population-based study conducted using secondary data from DATASUS, covering the period from 2016 to 2024. Results: between 2016 and 2024, a total of 214,082 cases of congenital syphilis and 520,891 cases of Zika virus infection were reported in Brazil, according to data from the Notifiable Diseases Information System (SINAN). Congenital syphilis showed persistently high numbers throughout the time series, with an increasing trend in recent years, indicating ongoing vertical transmission. In contrast, Zika virus infection exhibited an epidemic pattern, with a marked peak in 2016, followed by a decline and interannual fluctuations. A higher concentration of cases was observed in the Northeast and Southeast regions for both conditions. Regarding maternal characteristics, a greater occurrence was identified among women aged 20 to 29 years and those with lower educational levels, in addition to a significant proportion of records with missing or unknown data, suggesting potential weaknesses in the reporting system. These findings indicate an association with socially vulnerable contexts. Conclusions: the findings confirm these infections as relevant public health problems, highlighting the need to strengthen prevention, surveillance, and prenatal care to reduce regional inequalities.