Sexually transmitted infections (STIs) like chlamydia, syphilis, and gonorrhea are rising, particularly among men who have sex with men and transgender women. A UCSF and University of Washington study indicated that doxycycline post-exposure prophylaxis (doxy-PEP) can lower STI rates by two-thirds in high-risk groups. Participants at risk, who had a history of bacterial STIs and often had condomless sex, were given doxy-PEP or standard care. The doxy-PEP group saw around 10% of quarterly STI tests return positive, compared to 30% in the standard-care group, with gonorrhea incidence dropping by 55% and chlamydia and syphilis by over 80%. However, there was an observed slight increase in antibiotic-resistant bacteria among the doxy-PEP group.
This raises concerns about the future effectiveness of doxy-PEP, as it may contribute to antibiotic resistance, especially with strains of gonorrhea. Researchers emphasize monitoring resistance patterns over time and balancing potential benefits of reduced STIs against antibiotic resistance. They advocate for including doxy-PEP in sexual health strategies for those at high risk of STIs. Further study is needed to explore its impact across various populations.
