SAN FRANCISCO (KRON) – A new treatment has been shown to significantly reduce the chances of acquiring a sexually transmitted infection after sex, according to the results of a clinical trial announced by the San Francisco Department of Public Health on Thursday.

SFDPH made the announcement in a press release touting the end of the city’s monkeypox state of emergency, which will expire Oct. 31.

The new treatment, doxycycline post-exposure prophylaxis (doxy-PEP), can be used within 72 hours of vaginal, oral, and anal sex to prevent infection with the bacterias that cause gonorrhea, chlamydia and syphilis.

The clinical trial was conducted by SFDPH, UCSF, and the University of Washington.

“In particular, doxy-PEP holds promise to decrease rates of syphilis in San Francisco, which are among the highest in the country,” the press release stated. “Syphilis is also the STI with the highest potential for severe disease, particularly involving the eyes and nervous system.”

The trial included 630 participants from Seattle and San Francisco.

“At this point, doxycycline after sex is a targeted intervention for certain populations, in this case men who have sex with men or transgender women who have already had an STI in the past year,” stated Dr. Annie Luetkemeyer, a UCSF professor.

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Luetkemeyer compared doxy-PEP to the drugs used as pre-exposure prophylaxis (PrEP) to prevent HIV-negative people from acquiring the human immunodeficiency virus. 285,000 Americans are taking the anti-viral drugs Truvada or Descovy for that purpose.

SFDPH is recommending that a 200 milligram treatment be used by cisgender men and transgender women who’ve had a bacterial STI in the past 12 months and have reported condomless anal or oral sexual contact with at least one cis male or trans female partner in the past year.

“The guidance also recommends that anyone with a history of syphilis receive doxy-PEP,” the press release continued. “SFDPH will continue to support and participate in research that promotes the sexual health of the communities we serve.”

SFDPH said people should check in with their health providers to see if they should take doxy-PEP.

“We encourage people in those groups to contact their healthcare provider to discuss if doxy-PEP is right for them and how it can be best accessed,” SFDPH told KRON4 News.