Among patients with uncomplicated chlamydial genital infection, what is the most common anatomical site of infection in women?

Explanation

## Anatomical Sites of Chlamydial Infection in Women **Key Point:** The endocervix is the primary and most common site of Chlamydia trachomatis infection in women, accounting for >80% of genital chlamydial infections. ### Site-Specific Infection Frequency | Site | Frequency | Clinical Significance | |------|-----------|----------------------| | Endocervix | >80% | Primary site; columnar epithelium is target | | Urethra | 30–40% | Often concurrent with cervicitis | | Rectum | 5–10% | Associated with receptive anal intercourse | | Bartholin's glands | <5% | Rare; may cause Bartholin's cyst/abscess | **High-Yield:** Chlamydia has a **tropism for columnar epithelium** — it preferentially infects the endocervix (columnar) rather than the ectocervix (stratified squamous). This is why cervicitis (not vulvovaginitis) is the hallmark presentation. ### Clinical Presentation of Cervical Chlamydia 1. **Symptoms:** Often asymptomatic (50% of cases); when symptomatic: vaginal discharge, post-coital bleeding, dysuria 2. **Cervical findings:** Mucopurulent cervical discharge, cervical erythema, cervical friability, endocervical edema 3. **Diagnosis:** NAAT from endocervical swab (gold standard); nucleic acid amplification is more sensitive than culture 4. **Complications if untreated:** Pelvic inflammatory disease (PID), ectopic pregnancy, infertility, chronic pelvic pain **Clinical Pearl:** Many women with chlamydial cervicitis are **completely asymptomatic**, making routine screening essential in sexually active women <25 years and those with risk factors. Asymptomatic infection can still ascend to cause PID. ### Why Endocervix Is the Primary Site - **Epithelial tropism:** Chlamydia infects columnar epithelium; the endocervix is lined with columnar cells - **Ascending infection:** From endocervix, infection can ascend to the upper genital tract (uterus, fallopian tubes, ovaries) - **Reservoir:** The endocervix serves as the main reservoir for transmission to sexual partners ### Concurrent Urethritis Although the urethra is infected in 30–40% of women with cervical chlamydia, urethritis is often **asymptomatic or mild** because the female urethra is shorter and the infection is less likely to cause obstructive symptoms compared to male urethritis. **Mnemonic:** **C-Cervix** = **C**hlamydia targets the **C**ervix (columnar epithelium) in women. ### Screening Recommendations - **All sexually active women <25 years:** Annual screening - **Women ≥25 with risk factors:** Annual screening - **Pregnant women:** Screening at first prenatal visit; repeat in third trimester if high risk - **Specimen:** First-void urine or endocervical swab (NAAT preferred)