Trends in Sexually Transmitted Infections Associated With the Doxycycline Postexposure Prophylaxis Guidelines in San Francisco.

The San Francisco Department of Public Health was the first to issue guidance on the use of doxycycline for postexposure prophylaxis against sexually transmitted infections in at-risk populations. We investigated the association between the issuance of these guidelines and rates of male rectal chlamydia, male rectal gonorrhea, and adult male syphilis.