Association between prior antibiotic use and reduced chlamydia trachomatis infection prevalence: a cross-sectional study in China.

Background: Antibiotic use not only can treat chlamydia infection but may also have an impact on chlamydia transmission. This study assessed whether prior antibiotic use was associated with a lower prevalence of chlamydia infection among women in a country with high antibiotic consumption.

Methods: A cross-sectional study was conducted in 2019 among sexually active women aged 18-44 years in Guangdong Province, China. Participants seeking gynecological care underwent current chlamydia and gonorrhea testing using nucleic acid amplification. Antibiotic use in the past year was self-reported. Logistic regression models assessed the association between prior antibiotic use and the prevalence of chlamydia infection.

Results: This study surveyed 391 participants (average age: 31.5 ± 6.2 years). Among them, 41.2% (161/391) self-reported using at least one antibiotic in the past year, with amoxicillin being the most common. Chlamydia prevalence was 8.2% (32/391), while no gonorrhea cases were detected. After adjusting for age, age at first debut, and engaging in high-risk sexual behaviors, prior use of any antibiotics was associated with a lower prevalence of chlamydia infection (OR: 0.39, 95% CI: 0.16, 0.95). Among patients who had used the recommended regimens for chlamydia infection (azithromycin, amoxicillin, and/or erythromycin), the prevalence was low (5.3%). It showed a non-significant trend toward reduced prevalence of current chlamydia infection (OR = 0.40, 95% CI: 0.14, 1.10).

Conclusions: Recent antibiotic use is prevalent among women attending gynecological clinics in China. Overall, prior antibiotic use showed a trend towards being negatively associated with the prevalence of chlamydia infection. Further investigations in larger studies are warranted.