### Decline in STI Diagnoses Brings New Hope for Public Health Officials

In a surprising turn of events, those combating sexually transmitted infections (STIs) in the public health sector are witnessing a shift from a perpetual losing battle to one marked by hope. According to a recent report from the Centers for Disease Control and Prevention (CDC), overall diagnoses of the top three bacterial STIs have seen a slight decline since the onset of the COVID-19 pandemic. From 2022 to 2023, new cases decreased by 2%, totaling 2.46 million.

Among the most notable shifts, diagnoses of primary and secondary syphilis—stages of the infection considered highly contagious—dropped by 10% last year, amounting to 53,000 cases. This decrease was primarily driven by a 13% reduction in infections among gay and bisexual men, a group that, while only 2% of the adult population, has historically accounted for nearly half of these cases. Young people and racial minorities also face disproportionate impacts from STIs, with nearly half of all diagnoses in 2022 involving individuals aged 15 to 24, and nearly one-third of cases affecting Black Americans.

The report highlighted a 7% decline in gonorrhea cases, bringing the total to 601,300 in 2023. This followed a previous 9% decline the year before. Syphilis cases across all stages showed a slight increase of 1%, equating to 209,250 diagnoses. Meanwhile, chlamydia cases have remained relatively stable at approximately 1.65 million from 2021 to 2023.

Dr. Laura Bachmann, chief medical officer of the CDC's STI prevention division, commented, "I think we're at an inflection point, and it's important that we push forward and take advantage of innovations and investment in STI prevention going forward."

This turnaround, particularly in syphilis diagnoses among gay and bisexual men, is partially attributed to the adoption of an STI prevention method using the antibiotic doxycycline. Known as doxyPEP (doxycycline post-exposure prophylaxis), this protocol involves taking a 200-milligram tablet of doxycycline within 72 hours of condomless sex. Recent randomized controlled trials have shown doxyPEP to reduce cases of chlamydia and syphilis by more than 70% and gonorrhea by around 50% among gay and bisexual men.

San Francisco was the first city to recommend doxyPEP for gay and bisexual men and transgender women in October 2022, followed by the CDC in June. Other major cities, including Chicago and New York, have since adopted similar guidance. Early analyses suggest the method is gaining traction within the population, leading to notable declines in STI rates.

Experts hope these positive trends will extend to other vulnerable groups, such as women of childbearing age. A concerning rise in syphilis cases among newborns had public health officials alarmed, but recent increases in testing among pregnant women and the resolution of a shortage of Pfizer's Bicillin-LA, the recommended treatment for syphilis in pregnant women, have fostered optimism.

Additionally, the FDA's approval of the first at-home tests for gonorrhea and chlamydia in November 2023 is expected to aid in combating the spread of STIs. Moreover, ongoing research into another protocol, doxyPrEP, which involves daily doxycycline use, has shown promising results in different populations, such as female sex workers in Japan.

While these advancements mark significant progress, concerns remain regarding racial disparities and potential contributions to antibiotic resistance. Public health experts stress the importance of continued investment in STI-related care to build on these recent gains and ensure equitable access to prevention methods. Dr. Jeffrey Klausner of the University of Southern California underscores the need for renewed funding to sustain and expand effective STI prevention and treatment initiatives.