Abstract
This study analyzed the epidemiological profile of sexually transmitted infections (STIs), including syphilis and HIV, and viral hepatitis in Brazil between 2019 and 2023, using data from the Notification of Diseases Information System (SINAN) of the Brazilian Ministry of Health. Results show a predominance of cases among young adults (20–39 years), mainly men and individuals identifying as mixed race or white, with higher incidence in the Southeast and Northeast regions. Average education levels (complete elementary or high school) indicated that vulnerability is not limited to populations with low education. The COVID-19 pandemic impacted testing, reporting, and access to health services, causing a decline in cases in 2020, followed by recovery in subsequent years. The high proportion of incomplete records compromised the accuracy of analyses by sex, age, race, education, and region. The persistence of vertical syphilis transmission, gaps in maternal partner treatment, and structural inequalities highlight social, cultural, and economic barriers that limit the effectiveness of public policies. Statistical analyses confirmed significant patterns of age concentration, male predominance, and regional disparities. Young adults and women of reproductive age emphasize the need for reinforced prenatal care, universal testing, and timely treatment of the mother-partner dyad. Integrating social, behavioral, and biological determinants can inform public policies tailored to regional and social realities, strengthening combined prevention strategies, health education, contact tracing, and reduction of structural inequalities. The study demonstrates that addressing STIs and viral hepatitis in Brazil requires multidimensional, intersectoral, and evidence-based interventions, ensuring equity in access to health services, strengthening epidemiological surveillance, and providing comprehensive care to the most vulnerable populations.