Racial/ethnic disparities in the lifetime risk of Chlamydia trachomatis diagnosis and adverse reproductive health outcomes among women in King County, Washington.

Background: Chlamydia trachomatis is the most common reportable infection in the US and can cause pelvic inflammatory disease (PID) and tubal factor infertility (TFI).

Methods: We created lifetables to estimate the "lifetime" risk of chlamydia diagnosis among women age 15-34 in King County, Washington, US, 1992-2014. We estimated the lifetime risk of chlamydia-associated PID and TFI, incorporating published estimates of the risk of sequelae by chlamydia testing history.

Results: From 1992-2014, 51,464 first chlamydia diagnoses were reported among women age 15-34 in King County. For women born 1980-1984, the lifetime risk of chlamydia diagnosis was 19.8% overall and 14.0% for non-Hispanic white, 64.9% for non-Hispanic black, and 32.6% for Hispanic women. The cumulative risk of chlamydia by age 24 increased overall from 13.9% to 17.3% among birth cohorts born 1975-1994 but declined among non-Hispanic black women, among whom risk by age 24 peaked at 57.3% among women born 1980-1984 and declined to 38.6% among women born 1990-1994. The overall lifetime risk of chlamydia-associated PID among women born 1980-1984 ranged from 0.33-1.14%. Among non-Hispanic white, non-Hispanic black, and Hispanic women, the lifetime risk of chlamydia-associated TFI was 0.04%, 0.20%, and 0.10%, respectively.

Conclusions: The lifetime risk of chlamydia varies dramatically by race/ethnicity, with over 60% of non-Hispanic black women diagnosed with at least one infection by age 34 in the birth cohorts most affected, a risk almost five times that in non-Hispanic whites. An estimated one in 500 non-Hispanic black women develops chlamydia-associated TFI. More effective control measures are needed.