From the Guidelines
Chlamydia is the most common Sexually Transmitted Infection (STI) in the United States.
Key Points
- According to the US Preventive Services Task Force, chlamydia and gonorrhea are the most commonly reported STIs in the United States 1.
- In 2012, more than 1.4 million cases of chlamydial infection were reported to the CDC, with the true incidence likely being higher due to asymptomatic and undetected cases 1.
- Chlamydial infections are 10 times more prevalent than gonococcal infections in women aged 18 to 26 years, and the rate of chlamydial infection in females is more than double the rate in males 1.
- The CDC reported over 929,000 chlamydial infections in 2004, with the actual number of new cases estimated to be over 2.8 million per year due to underdetection and underreporting 1.
- Sexually active young women, particularly those under 24 years old, are at highest risk for chlamydial infection, with other risk factors including a history of STIs, new or multiple sexual partners, and inconsistent condom use 1.
- The high prevalence of chlamydia in the US is also highlighted by the CDC's 1998 guidelines, which recommend routine screening for chlamydial infection among sexually active adolescents and young adults 1.
- Additionally, the Advisory Committee for HIV and STD Prevention notes that the US has one of the highest rates of STDs in the industrialized world, with chlamydia being the most commonly reported infectious disease in 1996 1.
From the Research
Prevalence of Sexually Transmitted Infections (STIs) in the United States
- The most common STI in the United States is human papillomavirus (HPV) 2, 3, 4.
- According to a study published in 2015, HPV remains the most common STI, but new vaccinations have the possibility of having a significant impact on this virus's disease potential 2.
- A 2008 study estimated that approximately 6 million new HPV infections are acquired each year in the United States alone, and prevalence data suggest that as many as 24 million American adults may be infected with HPV 4.
- Another study published in 2013 estimated that HPV infections accounted for most of both prevalent and incident infections in the United States 3.
Incidence and Prevalence of STIs
- A 2021 study estimated that there were approximately 67.6 million prevalent and 26.2 million incident STIs in the United States in 2018 5.
- The same study found that chlamydia, trichomoniasis, genital herpes, and human papillomavirus comprised 97.6% of all prevalent and 93.1% of all incident STIs 5.
- A 2013 study estimated that there were approximately 110 million prevalent STIs among women and men in the United States in 2008, with HPV infections accounting for most of both prevalent and incident infections 3.
Demographic Characteristics of STI Prevalence
- A 2021 study found that persons aged 15 to 24 years comprised 18.6% of all prevalent infections, but 45.5% of all incident infections 5.
- A 2022 review found that populations with higher rates of STIs include people younger than 25 years, sexual and gender minorities, and racial and ethnic minorities 6.