Prevalence of Chlamydia trachomatis Infection in Young Women and Associated Predictors

Abstract

Background: Chlamydia trachomatis (CT) infection remains highly prevalent, and young women are disproportionately affected. Most CT-infected women are asymptomatic, and their infection often goes unrecognized and untreated. We hypothesized that testing for active CT infection with molecular diagnostics and obtaining a reported history of CT infection underestimate the prevalence of current and past CT infection, and incorporating serum CT antibody testing in addition to these other prevalence measures would generate more accurate estimates of the prevalence of CT infection in asymptomatic young women.

Methods: We enrolled 362 asymptomatic women aged 16 to 29 years at 4 different clinical settings in Birmingham, AL, between August 2016 and January 2020 and determined the prevalence of CT infection based on having 1 or more of the following prevalence measures: an active urogenital CT infection based on molecular testing, reported prior CT infection, and/or being CT seropositive. Multivariable regression analysis was used to determine predictors of the prevalence of CT infection after adjustment for participant characteristics.

Results: The prevalence of CT infection was 67.7% (95% confidence interval, 62.6%-72.5%). Addition of CT antibody testing to the other individual prevalence measures more than doubled the CT infection prevalence. Non-Hispanic Black race, reported prior gonorrhea, and reported prior trichomoniasis predicted a higher prevalence of CT infection.

Conclusions: More than half of women were unaware of ever having CT infection, suggesting many were at risk for CT-associated reproductive complications. These data reinforce the need to adhere to chlamydia screening guidelines and to increase screening coverage in those at risk.

Figure 1.

Different Chlamydia trachomatis (CT) infection prevalence measures and 95% confidence intervals (CIs) among 362 asymptomatic women enrolled in Birmingham, Alabama, 2016–2020: 1) CT nucleic acid amplification tests (NAAT) positive (+) (N = 18; 5.0%; 95% CI, 3.0%–7.7%), 2) reported prior CT infection (N = 102; 28.2%; 95% CI, 23.6%–33.1%), 3) CT NAAT+ and/or reported prior CT infection (N = 109; 30.1%; 95% CI, 25.4%–35.1%), 4) CT seropositive based on detection of CT-specific antibody by a CT elementary body ELISA (N = 230; 63.5%; 95% CI, 58.3%–68.5%), and 5) CT infection prevalence defined as the percentage of subjects with CT NAAT+, reported prior CT infection, and/or CT seropositive (N = 245; 67.7%; 95% CI, 62.6%–72.5%).