San Francisco’s STD curve finally bent downward in 2025. After years of watching infection counts climb around the country, the city reported a sharp drop in three major sexually transmitted infections and is crediting a big piece of the shift to aggressive prevention work and wider use of a post‑exposure antibiotic regimen known as doxy‑PEP. Health officials say the early results suggest that targeted biomedical tools layered on top of old‑fashioned screening and treatment can actually move the numbers. City clinics and community partners have spent the past few years boosting testing, treatment and easy access to the regimen for people at higher risk.
City data show syphilis fell 24%, chlamydia dropped 18% and gonorrhea declined 5% year over year, according to reporting by the San Francisco Chronicle. The largest declines were among men who have sex with men and transgender women, and officials released the numbers to coincide with National Sexually Transmitted Infection Awareness Week.
How San Francisco Rolled Out Doxy‑PEP
In October 2022, San Francisco’s health department issued the nation’s first public guidance on doxy‑PEP and began folding the regimen into services at City Clinic and into PrEP programs, according to SF Department of Public Health materials. Department slides document 3,779 cumulative doxy‑PEP initiations across three sentinel clinics between October 2022 and December 2023 and lay out how providers integrated the medication into routine HIV and sexual‑health care. Early uptake among higher‑risk groups had been tracked during the local rollout.
What the Science Shows
Randomized trials and implementation studies have found that doxy‑PEP can sharply cut rates of chlamydia and syphilis and has a more modest effect on gonorrhea, as reported in the New England Journal of Medicine and in follow‑up analyses. In June 2024, the federal government issued clinical guidance recommending that clinicians talk with gay and bisexual men and transgender women who have had a recent bacterial STI about doxy‑PEP and offer it through shared decision‑making as part of a broader prevention package, per the CDC.
Resistance and Trade‑offs
Public‑health experts stress that any rapid expansion of doxy‑PEP has to be balanced with the risk of fueling antibiotic resistance, particularly in Neisseria gonorrhoeae, and they have called for strong surveillance as programs grow. Modeling and surveillance work has highlighted rising resistance trends and the need for close monitoring, according to reporting in Emerging Infectious Diseases.
Where to Get Testing and What to Expect
Testing and treatment remain the backbone of San Francisco’s STI strategy, and many SFDPH clinics offer same‑day or otherwise low‑barrier services, including care for people without insurance, according to SF Department of Public Health materials. City Clinic and partner organizations also connect patients with HIV prevention options, vaccinations and partner services as part of a broader sexual‑health package.
“STI prevention is a key priority for SFDPH, and we are thrilled to see that doxy-PEP is making a difference in our communities,” Daniel Tsai, the city’s director of health, said in a statement to the San Francisco Chronicle. San Francisco Health Officer Dr. Susan Philip urged residents not to coast on the good news, telling the Chronicle, “We encourage the public to keep up the momentum by taking actions — such as getting tested — to protect their sexual health.” Officials say they will keep tracking case trends and resistance signals as services expand.
