San Francisco STI Surveillance Network (SSuN) Project - San Francisco (SF) is the only consolidated City and County in California; as such, the SF Department of Public Health (SFDPH) Population Health Division (PHD) is responsible for the health of its entire population. SF is home to an estimated 873,965 persons (2020 Census). There are numerous and distinctly diverse neighborhoods that are primarily characterized by dense housing and a range of socioeconomic strata, races, and ethnicities. Just over one third of the population is white non-Hispanic (39%); 34% is Asian, 16% is Hispanic or Latine, and 5% is Black/African American. Experiencing high disparities of STI and HIV rates, especially gonorrhea (GC) and syphilis, are an estimated nearly 70,000 men who have sex with men (MSM). From 2021 to 2022, the SF CT rate increased 4.3% to 6,465 cases for a rate of 739.7 per 100,000. The GC rate declined slightly by 0.3% to 5,247 cases, for a rate in 2022 of 600.4 per 100,000. Reported early syphilis (ES) declined to 1,122 cases in 2022, a 6% decrease for a 2022 rate of 128.4 per 100,000. San Francisco’s yearly GC and syphilis rates consistently exceed those for the Los Angeles Metropolitan Statistical Area (MSA), the New York MSA, the state of California, and the United States as a whole. As also seen nationally, SF has experienced a significant increase in the last 10 years in syphilis among females and congenital syphilis. Priority populations for STI prevention due to excess rates include gay, bisexual, and other MSM; adolescent and young adults, particularly youth of color; persons with or at risk of syphilis who are or can become pregnant; trans people; incarcerated people; and people experiencing homelessness. While syphilis in SF remains a disease predominantly among MSM, from 2017 through 2022, SFDPH observed a 215% increase in reported syphilis cases among women (from 59 to 186 cases). Most of the increase in syphilis among females both in SF and statewide is among women of childbearing age. In 2022, approximately 23% of female syphilis cases reported homelessness and 24% reported methamphetamine use. Building on successes and lessons learned from participating in SSuN since 2005, the SFDPH STI Program will be able to seamlessly continue its Strategy A protocols, updating them pending new refinements for SSuN Cycle 5, to conduct sentinel surveillance at San Francisco City Clinic (the only municipal STI clinic) through submission of visit-level records and routinely updated HIV diagnostic and laboratory data through eHARS-SFCC matches; and implementation of periodic patient surveys. We will also continue to contribute to the national conversation around quality of care and services in STI/Sexual Health settings with a focus on HIV PrEP and doxy-PEP surveillance metrics through Strategy C.2. The proposed work draws on SFDPH expertise in developing and maintaining robust clinical, surveillance systems, and extracting and matching data from the SFDPH HIV Registry and data-collection platforms. SFDPH SSuN Project staff include STI epidemiologists and program managers with extensive experience and skills in interpreting STI case, clinic visit, and patient survey data. The required collaboration across key SFDPH PHD Branches will enhance local and national understanding of trends and determinants of STIs in disproportionately impacted populations, effectively monitor health outcomes, and develop high impact prevention and other interventions to reduce STI morbidity and improve and monitor equitable uptake of HIV and STI preventive services in an EHE priority jurisdiction.