San Francisco sees massive drop in STIs

Health officials point to prevention efforts and a post-exposure antibiotic as key factors

Apr. 14, 2026 at 6:43pm by

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A translucent x-ray photograph revealing the ghostly outline of a human reproductive organ, conceptually representing the progress made in addressing sexually transmitted infections in San Francisco.San Francisco's innovative approach to STI prevention, including the use of doxy-PEP, has led to a significant decline in infection rates across the city.San Francisco Today

San Francisco has seen a sharp drop in sexually transmitted infections, with health officials citing prevention efforts and the growing use of doxycycline post-exposure prophylaxis (doxy-PEP) as key factors. New data shows syphilis cases fell 24% in 2025, while chlamydia dropped 18% and gonorrhea declined 5%. The declines were most pronounced among men who have sex with men and transgender women, populations historically hit hardest by STIs.

Why it matters

The significant decline in STI rates in San Francisco reflects the city's focus on sexual health and the success of innovative prevention strategies like doxy-PEP. This progress could serve as a model for other communities looking to address persistent public health challenges around STIs.

The details

According to the San Francisco Department of Public Health, the city saw a 24% drop in syphilis cases, an 18% decline in chlamydia, and a 5% decrease in gonorrhea in 2025 compared to the previous year. Officials say a major driver of this progress is the growing use of doxycycline post-exposure prophylaxis (doxy-PEP), a treatment taken after sex to help prevent certain bacterial STIs. The declines were most pronounced among men who have sex with men and transgender women, populations that have historically been disproportionately impacted by STIs.

  • The new data was released on April 14, 2026 to mark the start of National Sexually Transmitted Infection Awareness Week.
  • The figures show a decline in STI rates in San Francisco in 2025 compared to the previous year.

The players

San Francisco Department of Public Health

The local public health agency that released the data on the decline in STI rates in San Francisco.

Daniel Tsai

The director of health for the San Francisco Department of Public Health.

Dr. Susan Philip

The San Francisco Health Officer.

Dr. Stephanie Cohen

The official who oversees STI and HIV prevention and control for the San Francisco Department of Public Health.

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What they’re saying

“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, Director of Health, San Francisco Department of Public Health

“We are excited to see the progress being made in lowering STI diagnoses in San Francisco. We encourage the public to keep up the momentum by taking actions — such as getting tested — to protect their sexual health.”

— Dr. Susan Philip, San Francisco Health Officer

“The remarkable drop in STI cases in San Francisco is due in large part to the trailblazing work that made the rollout of doxy-PEP possible.”

— Dr. Stephanie Cohen, Overseer of STI and HIV prevention and control, San Francisco Department of Public Health

What’s next

The San Francisco Department of Public Health will continue to monitor STI trends and work to expand access to prevention and testing services, including for those without insurance.

The takeaway

San Francisco's success in reducing STI rates through innovative prevention strategies like doxy-PEP demonstrates the impact that a comprehensive, public health-focused approach can have on addressing persistent sexual health challenges. This progress could serve as a model for other communities looking to improve sexual health outcomes.