Chlamydia - Uncomplicated Anogenital Infection

Definition

Chlamydia trachomatis infection of the anogenital tract is a common sexually transmitted infection (STI) that is often asymptomatic but can cause urethritis, cervicitis, and mucopurulent discharge.

Epidemiology

• One of the most common STIs worldwide, particularly in sexually active adolescents and young adults.
• Higher prevalence in women than men due to increased likelihood of asymptomatic infection.
• Often coexists with other STIs, including gonorrhea.
• Underdiagnosed due to high rate of asymptomatic cases.

Etiology

• Caused by the obligate intracellular bacterium Chlamydia trachomatis (serovars D-K).
• Transmission primarily through sexual contact (vaginal, anal, or oral).
• Perinatal transmission from mother to newborn can cause conjunctivitis or pneumonia.
• Risk factors: multiple sexual partners, inconsistent condom use, previous STI, age <25 years.

Pathophysiology

• Bacteria infect epithelial cells of the urogenital tract.
• Intracellular replication leads to host cell damage and local inflammation.
• Immune response may cause mucopurulent discharge and urethral/cervical inflammation.
• Persistent infection can result in chronic inflammation and complications such as pelvic inflammatory disease (PID) in women.