Chlamydia is a bacterial infection, caused by Chlamydia trachomatis. It is the most common bacterial sexually transmitted infection (STI) worldwide, occurring most frequently among young sexually active adults. The prevalence of C. trachomatis infection is highest among girls aged 15–19 years, followed by young women aged 20-24 years.
C. trachomatis is spread by having unprotected vaginal, anal, or oral sex with someone who has chlamydia, or from mother-to-child during childbirth.
C. trachomatis causes cervicitis in women and urethritis in men, as well as extra-genital infections, including rectal and oropharyngeal infections. Untreated chlamydial infection may cause severe complications for the reproductive health of women including infertility. Maternal infection is associated with serious adverse outcomes in neonates. Chlamydia diagnosis is usually based on laboratory tests, and uncomplicated infection can be easily cured with antibiotics, and is usually resolved within days or weeks.
Lymphogranuloma venereum (LVG), a genital ulcer disease (GUD) that affects lymphoid tissue is caused by a more invasive strain (serovar) of C. trachomatis, and it is increasingly prevalent among men who have sex with men (MSM) in some settings.
Non-ulcerative STIs, such as gonorrhea, chlamydial infection and trichomoniasis, have been shown to increase STI transmission, including HIV transmission and acquisition. Additionally, 10-40% of people with gonorrhea infection also have a Chlamydia infection.
Uncomplicated Chlamydia can be easily cured with antibiotics and is usually resolved within days or weeks. Approximately 70% of women and 50% of men do not show any symptoms from genital infections due to Chlamydia.
- The global response to STI is currently guided by the Global health sector strategy on sexually transmitted infections, 2016 -2021.
- The Plan of Action for the Prevention and Control of HIV and Sexually Transmitted Infections (2016-2021) describes the strategic lines of action to be implemented by Member States and PAHO to enhance and expand the prevention and control of HIV and STIs in the Americas.
- In 2016, WHO launched the Guidelines for the Treatment of Chlamydia trachomatis, which provide updated treatment recommendations for common infections caused by Chlamydia trachomatis based on the most recent evidence