A 26-year-old woman presents with mucopurulent cervical discharge, dysuria, and pelvic pain. Nucleic acid amplification test (NAAT) is positive for *Chlamydia trachomatis*. What is the most common site of infection in women with chlamydial genital infection?

Explanation

## Most Common Site of Chlamydial Infection in Females **Key Point:** The cervix is the most common site of *Chlamydia trachomatis* infection in women, accounting for >80% of genital chlamydial infections. ### Why the Cervix? *Chlamydia trachomatis* preferentially infects columnar epithelium. In females, the endocervix is lined with columnar epithelium, making it the primary target organ: 1. **Epithelial tropism:** The organism has a strong affinity for columnar epithelium 2. **Anatomical accessibility:** The endocervix is the most exposed columnar epithelium in the female genital tract 3. **Initial inoculation site:** During sexual contact, the organism first encounters and colonizes the cervical mucosa ### Sites of Chlamydial Infection in Females (by frequency) | Site | Frequency | Clinical Features | Notes | |------|-----------|-------------------|-----------| | Cervix (endocervix) | Most common (>80%) | Mucopurulent discharge, cervicitis | Primary site | | Urethra | Common (30–50%) | Dysuria, urethritis | Often concurrent with cervicitis | | Rectum | Less common (5–10%) | Often asymptomatic | More common in MSW | | Bartholin glands | Rare | Bartholinitis | Uncommon presentation | | Upper genital tract | Variable | PID, salpingitis | Ascending infection | **High-Yield:** Chlamydial cervicitis is often asymptomatic or minimally symptomatic, making screening crucial. NAAT (nucleic acid amplification test) is the gold standard for diagnosis and has >95% sensitivity and specificity. **Clinical Pearl:** Unlike gonorrhea, which typically causes acute purulent urethritis in males, chlamydia in females most commonly presents as cervicitis. Many infected women are asymptomatic, which is why routine screening is recommended for sexually active women <25 years and those with risk factors. **Mnemonic:** **CHLAMYDIA CERVIX** — In females, think **Cervix** as the primary site. The organism loves **Columnar epithelium**, and the **Cervix** is the main columnar-lined structure in the female genital tract. **Warning:** Do not confuse chlamydial infection patterns with gonococcal patterns. While gonorrhea causes acute anterior urethritis in males, chlamydia causes cervicitis in females. Both organisms can infect multiple sites, but the primary and most common sites differ by gender and organism.