Chlamydia

Chlamydia is a bacterial sexually transmitted infection caused by Chlamydia trachomatis, and one of the most commonly reported STIs among sexually active young adults worldwide. It is often called a "silent" infection because up to 70-80% of infected women and a substantial proportion of infected men have no noticeable symptoms, allowing the infection to persist undetected and, in women, ascend into the upper reproductive tract where it can cause lasting damage. The infection is easily and reliably cured with a short course of antibiotics, but only if it is diagnosed, which is why routine screening in sexually active young people is recommended regardless of symptoms.

Most infections, particularly in women, cause no symptoms. In women, when present: • Abnormal vaginal discharge • Burning sensation during urination • Pain during intercourse • Bleeding between periods or after sex • Lower abdominal or pelvic pain In men, when present: • Discharge from the penis • Burning sensation during urination • Pain and swelling in one or both testicles (epididymitis) Rectal or throat infections from anal or oral sex are often entirely asymptomatic and are only detected through targeted testing.

Chlamydia trachomatis is a bacterium transmitted through vaginal, anal, or oral sexual contact with an infected partner. It can also be transmitted from an infected mother to her baby during vaginal delivery, potentially causing conjunctivitis or pneumonia in the newborn. Because it frequently causes no symptoms, infected individuals often unknowingly transmit it to partners.

• Age under 25, the group with the highest infection rates • Multiple sexual partners or a new sexual partner • Inconsistent or no condom use • Previous chlamydia or other STI diagnosis • Having a sexual partner with an untreated STI

• Pelvic inflammatory disease (PID) in women, from the infection ascending into the uterus, fallopian tubes, and ovaries, causing chronic pelvic pain and scarring • Tubal factor infertility, from scarring of the fallopian tubes after PID • Ectopic pregnancy, a life-threatening complication caused by tubal scarring • Epididymitis in men, which can occasionally affect fertility • Reactive arthritis, an uncommon complication involving joint inflammation following infection • Neonatal conjunctivitis or pneumonia if transmitted to a baby during childbirth • Increased risk of acquiring or transmitting HIV

• Use condoms consistently and correctly during vaginal, anal, and oral sex • Get tested regularly if sexually active with multiple partners, particularly for women under 25 • Both partners should be treated simultaneously and avoid sexual contact until treatment is complete, to prevent reinfection ("ping-pong" transmission between partners) • Limit the number of sexual partners and discuss STI testing history with new partners