Sexually transmitted infections among active component members of the U.S. Armed Forces, 2016-2024.

This report summarizes incidence rates and trends of the 5 most frequently occurring sexually transmitted infections (STIs) from 2016 through 2024 among active component service members of the U.S. Armed Forces. The data for this report were derived from medical and public health surveillance of chlamydia, gonorrhea, and syphilis as nationally notifiable diseases; case data for 2 additional STIs, human papillomavirus (HPV) and genital herpes simplex virus (HSV), are also presented. Chlamydia infections were the most common during the surveillance period, followed, in decreasing order of frequency, by HPV, gonorrhea, genital HSV, and syphilis. In 2024, both chlamydia and gonorrhea rates dropped to their lowest points of the period of surveillance, falling 25.5% and 26.4%, respectively, from their 2019 peaks. Declines were predominantly concentrated among service members younger than 25 years of age-who were the largest contributors to overall incidence. Notably, syphilis incidence rose steadily throughout the surveillance period, among all age groups, and both sexes, with steepest rises after 2021, increasing nearly 70%. Non-Hispanic Black service members continue to bear the highest syphilis burden, among whom incidence peaked in 2023, before declining approximately 15% in 2024. Syphilis rates continued to rise among all other racial and ethnic groups through 2024, with the largest relative increase, 456%, among non-Hispanic White service women under age 25 years. Genital HSV demonstrated a downward trend throughout the surveillance period, with overall incidence reaching its lowest point in 2024. Incidence of genital HPV also decreased among all service members, with a more pronounced decrease among men. Chlamydia, gonorrhea, and genital HSV incidence rates dropped to their lowest points of the 9-year surveillance period. In contrast, total syphilis incidence rose among all age groups, and both sexes, with the highest incidence among service women ages 17-19 years. While syphilis incidence rates remain highest among non-Hispanic Black service members, its incidence has risen sharply in all other racial and ethnic groups, reflecting an evolving and expanding syphilis epidemiology within the military in addition to the general U.S. population.