A 28-year-old woman presents with dysuria, mucopurulent cervical discharge, and lower abdominal pain for 10 days. She is sexually active with a single partner. On examination, cervical motion tenderness is present. Nucleic acid amplification test (NAAT) for Chlamydia trachomatis is positive. Her partner is asymptomatic. What is the most appropriate next step in management?

Explanation

## Clinical Context This is a case of uncomplicated urogenital Chlamydia trachomatis infection in a woman with cervicitis and signs of lower genital tract involvement. The positive NAAT confirms the diagnosis. ## Management Principles for C. trachomatis Urogenital Infection **Key Point:** Uncomplicated chlamydial cervicitis requires: 1. Appropriate antibiotic therapy 2. **Mandatory partner notification and treatment** (even if asymptomatic) to prevent reinfection and break transmission chain 3. Test of cure is NOT routinely recommended (NAAT can remain positive for weeks) ## Recommended Regimens | Regimen | Dose | Duration | Notes | |---------|------|----------|-------| | **Doxycycline** | 100 mg PO BD | 7 days | **First-line for non-pregnant women** | | Azithromycin | 1 g PO single dose | Single dose | Alternative; less preferred now due to resistance | | Ceftriaxone | 250 mg IM | Single dose | Reserved for gonorrhea co-infection or allergy | **High-Yield:** The 2021 CDC/WHO guidelines recommend doxycycline 100 mg twice daily for 7 days as first-line for uncomplicated chlamydial urogenital infection, with azithromycin as second-line due to emerging resistance. ## Why Partner Treatment is Mandatory **Clinical Pearl:** Asymptomatic partners of chlamydia-positive patients have a **30–50% probability of being infected** and are a source of reinfection. Empiric treatment of partners (without waiting for their test results) is standard practice and prevents: - Reinfection of the index patient - Progression to pelvic inflammatory disease (PID) in female partners - Urethritis and epididymitis in male partners - Vertical transmission in pregnancy ## Why Option 1 (Azithromycin + Defer Partner Treatment) Is Suboptimal - **Azithromycin:** Increasing resistance rates (>10% in many regions); single-dose regimen has lower efficacy compared to 7-day doxycycline - **Deferring partner treatment:** Violates standard of care; allows reinfection and ongoing transmission ## Why Option 3 (Pelvic Ultrasound Before Treatment) Is Incorrect - **No clinical indication:** Ultrasound is not part of the diagnostic workup for uncomplicated cervicitis - **Delays treatment:** Unnecessary imaging delays appropriate antimicrobial therapy - **Ultrasound role:** Reserved for suspected complications (tubo-ovarian abscess, severe PID) — not present here ## Why Option 4 (Ceftriaxone) Is Incorrect - **Not indicated:** Ceftriaxone is used for gonorrhea (especially with resistance concerns) or when co-infection is suspected - **No gonorrhea data:** The stem gives no clinical or microbiological evidence of concurrent gonorrhea - **Suboptimal for chlamydia monotherapy:** Doxycycline is superior for uncomplicated chlamydial infection **Mnemonic:** **DOX-7-BOTH** — Doxycycline 100 mg BD for 7 days, treat BOTH patient and partner