Background: Although Chlamydia trachomatis infection is known to be common among young women in the United States, information on cumulative risk of infection is limited.
Methods: We determined the cumulative risk of being reported as having chlamydia for all women living in Florida by analyzing surveillance records of 14–34 year-old women in Florida who were reported as having chlamydia between 2000 and 2011 and census estimates on the number of women in Florida. We first calculated reported infections per woman. Next, we limited analysis to first-infections and accumulated the risk of first-infection over the 11-year period to get cumulative risk. Finally, we looked at cumulative risk of repeat infection by age, over the 11-year period.
Results: During 2000–2011, there were 457,595 infections reported among 15–34-year-old women, with annual infection totals increasing every year from 25,390 to 51,536. 19-year-olds were at highest risk (5.1 infections diagnosed per 100 women in 2011). 341,671 different women were infected. Among women ages 14–17 in 2000, over 20% had at least one infection reported within 12 years, and among non-Hispanic blacks, this risk was over 36% even though 18% of reports were missing race/ethnicity information. Repeat infections were common. Among the 53,109 women reported with chlamydia at ages 15–20 during 2000–2003, 36.7% were reported with one or more additional infections by 2011.
Conclusions: The risk of chlamydia was high for young women in Florida. We found 36% of young black women in Florida had at least one reported infection between 2000 and 2011. Considering undiagnosed infections and reported infections where race was missing, probably over 50% of young black women in Florida acquired chlamydia at some point. Women who get chlamydia once, are likely to get it again. More information is needed on how to prevent chlamydial infection.