HIV vs STI Graph

Last updated October 3, 2022

From 2017 to 2021, the number of new HIV diagnoses in San Francisco decreased by 33%, while the number of chlamydia diagnoses decreased by 32%, syphilis diagnoses increased by 12%, and gonorrhea diagnoses decreased by 9%. These declines follow 7 years of steadily increasing rates and are likely related to a steep decline in STI screening during the COVID-19 pandemic.

San Francisco was one of the first urban centers to see declines in new HIV diagnoses, with new HIV diagnoses reduced by 65% from 462 in 2010 to 160 in 2021.1 These decreases are due to citywide efforts to scale-up HIV testing and early and widespread HIV treatment, a strong linkage-to-HIV care program (provided by the SFDPH LINCS team), and access to syringes, condoms, and more recently PrEP (pre-exposure prophylaxis for HIV).

Across this same time-period, condom use has been declining among gay men and other men who have sex with men.  This decrease is likely because taking PrEP (if you’re HIV-negative) or maintaining an undetectable HIV viral load (if you’re living with HIV) can prevent HIV acquisition and transmission, respectively, during sex, regardless of whether or not condoms are used.

Declining rates of condom use2 has likely contributed to rising rates of gonorrhea, syphilis and chlamydia in San Francisco. The San Francisco Department of Public Health is focused on reducing STI health disparities and preventing the most severe complications of STIs in San Francisco.  We prioritize our work with:

  1. gay, bisexual, and other men who have sex with men (MSM)
  2. adolescents and young adults, particularly those of color
  3. transgender persons and
  4. females of reproductive age who are at risk for syphilis infection (and therefore newborns with congenital syphilis).


  • Over 95% of new early syphilis cases in San Francisco are among men
  • From 2017 to 2021, there was a 3.7% increase in total syphilis diagnoses in men (1582 to 1642) and a 200% increase in total syphilis in women (59 to 177).
  • Between 2017 to 2021, there were 13 total congenital syphilis (CS) cases in SF, a 333% increase compared to the prior 5 years (2012-2016).


  • The number of chlamydia diagnoses decreased by 32% (9148 to 6199) in San Francisco between 2017 and 2021.
  • Adolescent and young adult women experience disproportionate rates of chlamydial infection, more so among black/African-American youth. There are multiple factors that contribute to these persistent disparities.


  • Between 2017 and 2021, the number of gonorrhea cases decreased by 9% (5797 to 5264) in San Francisco.
  • In 2021, over 60% of gonorrhea cases among males in San Francisco were identified through rectal and pharyngeal (throat) infections, highlighting the importance of extra-genital testing in addition to urine/urethral testing.
1 The HIV Epidemiology Annual Report 2021, available at
2 Chen YH, Guigayoma J, McFarland W, Snowden JM, Raymond HF. Increases in Pre-exposure Prophylaxis Use and Decreases in Condom Use: Behavioral Patterns Among HIV-Negative San Francisco Men Who have Sex with Men, 2004-2017. AIDS Behav 2019; 23(7): 1841-1845. Article