Estimating State-Level Chlamydia and Gonorrhea Incidence and Prevalence Among Women in the United States, 2019-2023: Mathematical Modeling Analysis.

Background: Estimates of chlamydia and gonorrhea prevalence and incidence have typically focused on national-level epidemiology. Disaggregated estimates are useful for local public health decision making. Methods: We developed a bayesian hierarchical modeling framework to estimate the incidence and prevalence of chlamydia and gonorrhea for women in the United States. The model was calibrated to indicators from different data sources, including state- and age-specific laboratory test positivity (data pooled over 2019-2023) and diagnosis rates (average of 2019-2023). At the national level, we calibrated to chlamydia prevalence and test coverage. We used the model to estimate state- and national-level prevalence, incidence, and screening rates among women by state and age (15-24, 25-34, 35-44, 45-54, ≥55 years). Results: For women aged 15 to 24 years, national-level chlamydia prevalence was estimated at 4.6% (95% uncertainty interval, 4.2%-4.9%), gonorrhea prevalence was 0.4% (0.4%-0.5%), and testing coverage was 33.4% (33.1%-33.7%). Across states, corresponding chlamydia incidence estimates were 1.9 to 3.1 times as high as observed diagnosis rates; gonorrhea incidence estimates were 3.3 to 4.7 times as high as diagnosis rates. Chlamydia prevalence in women aged 15 to 24 years ranged from 2.3% to 7.8% across states, and chlamydia incidence ranged from 2.8% to 12.4%. Gonorrhea prevalence ranged from 0.09% to 1%, and gonorrhea incidence ranged from 0.5% to 6.0%. Conclusions: This study presents a new analytic framework for estimating incidence and prevalence at the state level. By integrating laboratory, diagnosis, and survey data, we provide more granular, actionable estimates of sexually transmitted infection burden.