Changing epidemiology of reproductive tract infections in Western China: a three-phase retrospective study during the COVID-19 pandemic

We conducted a retrospective analysis of data to determine the positive rates of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Ureaplasma urealyticum (UU) in a cohort of outpatients in Suining, China, across various periods of the COVID-19 pandemic response. A retrospective study was conducted using outpatient data from the Suining Central Hospital, which was stratified into pre-pandemic (between January 2018 and January 2020), during-pandemic (January 2020 and January 2023), and post-pandemic (January 2023 and December 2024) periods. Following detection by real-time fluorescent RNA isothermal amplification (simultaneous amplification and testing) for CT, MG, UU, and NG, statistical analyses were performed to assess differences in outcomes by stage, sex, and age group. Among 6,086 CT, 7,321 MG, 15,232 UU, and 4,514 NG tests, significant epidemiological shifts were observed. Positivity rates for CT, MG, and UU were significantly higher during the pre-pandemic period (7.64%, 8.64%, and 54.10%, respectively) than those during (3.82%, 2.22%, and 44.74%, respectively) and after (3.57%, 3.89%, and 42.61%, respectively; all p < 0.01) the pandemic. NG exhibited a distinct pattern, with the lowest rate during the pandemic (5.20%) and rebound to 7.45% after the pandemic. Sex-specific analysis revealed that NG remained predominant among males throughout the phases, whereas UU was consistently predominant among females. CT demonstrated a notable transition from male predominance during the pre-pandemic period to comparable rates between sexes in subsequent phases. Age distribution showed that adolescents (≤ 20 years) had the highest risk for CT and NG across all the study periods. This single-center study in Western China revealed differential epidemiological shifts among four key reproductive tract pathogens during the COVID-19 pandemic. The positivity rates for CT, MG, and UU declined significantly during the pandemic, whereas that of NG rebounded during the post-pandemic phase. The positivity rate of CT transitioned from male predominance to comparable levels between sexes, and adolescents (≤ 20 years) had the highest-risk for CT and NG throughout all the periods. Our findings suggest that pandemic-related measures may have affected pathogen transmission, highlighting the need for sustained NG surveillance and targeted adolescent sexual health interventions in the post-pandemic era.