Chlamydia and Gonorrhea Incidence and Residential Segregation: US Spatiotemporal Patterns (2013-2021).

Objective: Investigate how residential segregation is associated with chlamydia and gonorrhea incidence between 2013 and 2021.

Methods: National-level secondary US data from 2013-2021 from the Centers for Diseases Control and Prevention Sexually Transmitted Infection surveillance dataset, American Community Survey, and Racial Segregation Index were analyzed using the Generalized Estimating Equation, and spatial regression. Analysis was divided into two periods (2013-2019; 2020-2021) to account for COVID-19 disruptions. Residential segregation was measured by dissimilarity index categorized into reference (<□0.25), moderate (0.26-0.50), high (0.51-0.75), and extreme (>□0.75) levels. Primary outcome measures were chlamydia and gonorrhea incidence rates. Residential segregation was the key independent variable with other social determinants of health covariates. 3058 counties within the contiguous United States were included within this study. Counties with missing data, and not within the contiguous United States were excluded.

Results: For chlamydia, from 2013-2019, segregation coefficients (i.e.,13.77 and 15.84 for moderate and high segregation) indicate that greater residential segregation is associated with higher chlamydia incidence rates (P<.0001). From 2020-2021, these coefficients increased (from 13 and 15 to 28.25 and 34.16), suggesting growing segregation-driven disparities. Gonorrhea followed a similar trend, with the coefficients increasing from 0.47 and 0.55 (P < .001) to 1.53 and 1.62 (P < .05), respectively. Spatial variation in the association between segregation and chlamydia incidence remained consistent, with stronger associations in the Southeastern, Midwest, and Western regions. Spatial variation in the association between segregation and gonorrhea incidence was more pronounced in the South and parts of the Midwest, with weaker associations in some Northern and Western regions.

Conclusions: Residential segregation remained a substantial driver of chlamydia and gonorrhea transmission. The spatial patterns varied over time for both diseases. Further research should extend post-COVID-19 analysis to assess evolving relationships between residential segregation and STI incidence across U.S. regions.

Key Points: Chlamydia and gonorrhea in 2023 were the most reported sexually transmitted infections in the United States, disproportionately affecting Black Americans. This study found that racial residential segregation was a substantial driver of chlamydia and gonorrhea transmission, especially during the COVID-19 pandemic. Study findings suggest that interventions aiming to reduce chlamydia and gonorrhea incidence rates in the United States should also include intervention activities that address adversities associated with racial residential segregation.