Temporal Distribution of Syphilis by Health Macro-Regions in the State of Santa Catarina, Brazil, in the Pre-, Pandemic, and Post-Pandemic Covid-19 Periods

Despite the global epidemiological transition since the 1970s toward a predominance of noncommunicable diseases, sexually transmitted infections such as syphilis remain major public health concerns in countries like Brazil. Syphilis, in its acquired, gestational, and congenital forms, has high transmissibility and significant maternal–infant repercussions, particularly in contexts of vulnerability and instability within healthcare services.This study analyzed the temporal distribution of syphilis across the health meso-regions of Santa Catarina, Brazil, in the pre-pandemic (2018–2019), pandemic (2020–2021), and post-pandemic (2022–2023) periods. Ecological time-series study using secondary data from the national Notifiable Diseases Information System for the three forms of syphilis. Analyses were stratified by period and health meso-region: North and Northern Planalto, Greater West, Mid-West and Serra, Foz do Itajaí Region, Itajaí Valley, Greater Florianópolis, and South. Across the period, there were significant variations in case distribution. Congenital syphilis recorded 1,222 notifications pre-pandemic, 1,065 during the pandemic, and 1,316 post-pandemic, with the highest concentration in Greater Florianópolis. Acquired syphilis had 23,573 cases pre-pandemic (predominant in North and Northern Planalto), 22,912 during the pandemic, and a marked increase post-pandemic with 34,397 cases, concentrated in Greater Florianópolis. Gestational syphilis also increased: 4,241 pre-pandemic, 4,428 during the pandemic, and 5,964 post-pandemic. Greater Florianópolis had the highest case counts in the first two periods, being surpassed by North and Northern Planalto in the post-pandemic period. The data show spatial and temporal shifts in syphilis distribution in Santa Catarina, especially after COVID-19, suggesting negative impacts on epidemiologic surveillance and continuity of sexual and reproductive health care. Results reinforce the urgency of strengthening regional strategies for prevention, screening, and treatment of STIs, emphasizing coordination between primary care and health surveillance, particularly during health crises.