One potential STD prevention strategy has emerged, but its efficacy is hotly debated — using doxycycline as PrEP.

In recent years, there has been a trending rise in STDs in the United States, forcing experts to look for alternative prevention strategies.                                                                                  In 2018, the STD epidemics of gonorrhea, chlamydia, and syphilis reached all-time highs after 5 years of dramatic increases — trends that show no sign of slowing. As STDs rise, innovation to address the worsening STD crisis has lagged and STD programs and clinicians are often forced to use decades-old prevention strategies, biomedical interventions and diagnostic technologies. There is a growing need for new tools to address these worsening epidemics. In September 2019, leaders at the NIH echoed this need and called for innovative research to surmount this “growing global health crisis.”

One potential STD prevention strategy has emerged, but its efficacy is hotly debated — using doxycycline as PrEP. A 2015 pilot study of 30 HIV-positive men who have sex with men with prior syphilis infections demonstrated that doxycycline may be effective in reducing STD incidence. Significant findings included a 73% decrease in syphilis, gonorrhea and chlamydia when half the participants were assigned doxycycline as PrEP, but the study was too small to make many other conclusions. The threat of antibiotic resistance, especially in gonorrhea, is cited as a concern. However, contingent upon advancements in alternative treatments for gonorrhea, doxycycline as PrEP could be useful for the prevention of new syphilis and chlamydia cases.

There are a few studies currently looking at doxycycline for PrEP, but overall, research is limited. 

As rates continue to climb, bringing STD prevention strategies into the 21st century is becoming increasingly urgent. Mounting a defense against this growing threat will require continued and novel investment in STD research, a field that is perennially underfunded and not considered a priority. Increased investment in research now will go a long way in curbing STDs in the future.                Infectious Disease News asked David C. Harvey, MSW, executive director of the National Coalition of STD Directors

• References:
• Bolan RK, et al. Sex Transm Dis. 2015;doi:10.1097/OLQ.0000000000000216.
• CDC. Sexually transmitted disease surveillance 2018. https://www.cdc.gov/std/stats18/STDSurveillance2018-full-report.pdf. Accessed October 25, 2019.
• NIH. NIAID officials call for innovative research on sexually transmitted infections. https://www.nih.gov/news-events/news-releases/niaid-officials-call-innovative-research-sexually-transmitted-infections. Accessed October 25, 2019.
• Treatment Action Group. Gonorrhea, chlamydia, and syphilis pipeline report 2019. http://www.treatmentactiongroup.org/sites/default/files/pipeline_gonorrhea_chlamydia_syphilis_final.pdf. Accessed October 25, 2019.

Disclosure: Harvey reports no relevant financial disclosures.