A 28-year-old woman presents to the outpatient clinic with a 3-week history of mucopurulent cervical discharge and dysuria. She is sexually active with a new partner 6 weeks ago. Pelvic examination reveals cervicitis with a friable cervix. Nucleic acid amplification test (NAAT) on endocervical swab is positive for Chlamydia trachomatis. Her partner is asymptomatic. Which of the following is the most appropriate next step in management?

Explanation

## Diagnosis and Clinical Context **Key Point:** Chlamydia trachomatis is the most common bacterial sexually transmitted infection (STI) in India and worldwide. It causes urogenital infection in both men and women, often with minimal or asymptomatic presentation in males. ## Treatment Regimen for Uncomplicated Urogenital Chlamydia | Regimen | Dosing | Notes | |---------|--------|-------| | **Doxycycline (DOC)** | 100 mg PO BD × 7 days | First-line; excellent intracellular penetration; contraindicated in pregnancy | | Azithromycin | 1 g single dose | Alternative; less effective than doxycycline; higher resistance rates emerging | | Amoxicillin | 500 mg TDS × 7 days | Used in pregnancy only | | Ceftriaxone | 250 mg IM × 1 | For gonorrhea co-infection; NOT monotherapy for chlamydia | **High-Yield:** Doxycycline 100 mg twice daily for 7 days is the **gold standard** for uncomplicated urogenital chlamydia in non-pregnant women [cite:Park 26e Ch 16]. ## Partner Management **Clinical Pearl:** Partner notification and treatment are **mandatory**, not optional. All sexual partners within the preceding 60 days must be tested and treated to prevent reinfection and reduce transmission. Asymptomatic male carriers are a major reservoir for continued spread. **Mnemonic:** **TREAT** — **T**est and **R**eport all **E**xposed **A**nd **T**reated partners. ## Why Culture Is Not Needed Chlamydia trachomatis is an obligate intracellular pathogen that is difficult and slow to culture (requires cell culture on McCoy or HeLa cells, not Thayer-Martin medium). NAAT (PCR, TMA, SDA) has >95% sensitivity and specificity and is the diagnostic gold standard. Once NAAT is positive, treatment should begin immediately without waiting for culture confirmation. ## Contraindications and Alternatives - **Doxycycline is contraindicated in pregnancy** (teratogenic — causes permanent tooth discoloration and enamel hypoplasia in the fetus). Use amoxicillin 500 mg TDS for 7 days in pregnant women. - **Azithromycin monotherapy** is no longer recommended as first-line due to emerging resistance and lower efficacy compared to doxycycline. - **Ceftriaxone** is used for gonorrhea and is part of combination therapy for suspected dual infection (chlamydia + gonorrhea), but is NOT monotherapy for chlamydia alone.