MMWR Morb Mortal Wkly Rep. 2011 Apr 1;60(12):370-3.
hlamydia, a sexually transmitted infection caused by the bacterium Chlamydia trachomatis, is the most commonly reported nationally notifiable disease. A total of 1,244,180 cases were reported in 2009. However, many infections are not detected, and an estimated 2.8 million infections occur each year. The burden of infection is greatest among sexually active adolescents and young adults; chlamydia prevalence among sexually active persons aged 14--24 years is nearly three times the prevalence among those aged 25--39 years (National Health and Nutrition Examination Survey 1999-2008 [NHANES], unpublished data, 2011). Substantial racial/ethnic disparities in chlamydial infection exist, with prevalence among non-Hispanic blacks approximately five times the prevalence among non-Hispanic whites. Among sexually active females aged 14--19 years, chlamydia prevalence is 6.8% overall (4.4% among non-Hispanic whites and 16.2% among non-Hispanic blacks).
衣原体，一种由衣原体细菌引起的性传播感染，是全国报告最多的法定传染病。2009 年共报告了 1244180 例病例。然而，许多感染并未被发现，估计每年有 280 万例感染。感染的负担在性活跃的青少年和年轻人中最大；在 14-24 岁的性活跃人群中，衣原体的流行率几乎是 25-39 岁人群的三倍（1999-2008 年全国健康和营养调查[NHANES]，未发表数据，2011 年）。衣原体感染存在着明显的种族/族裔差异，非西班牙裔黑种人的流行率大约是非西班牙裔白种人的五倍。在 14-19 岁的性活跃女性中，衣原体的总体流行率为 6.8%（非西班牙裔白种人为 4.4%，非西班牙裔黑种人为 16.2%）。
