A 24-year-old woman from Mumbai presents with mucopurulent cervical discharge, dysuria, and lower abdominal pain for 10 days. She reports unprotected sexual contact 2 weeks ago. On speculum examination, there is a thick, yellow cervical discharge with cervical erythema and friability. Gram stain of the cervical discharge shows no gram-negative diplococci. Nucleic acid amplification test (NAAT) for *Chlamydia trachomatis* is positive; gonorrhea NAAT is negative. What is the most appropriate treatment?

Explanation

## Clinical Diagnosis and Investigation Findings **Key Point:** The patient has confirmed *Chlamydia trachomatis* infection (positive NAAT) with negative gonorrhea NAAT. The absence of gram-negative intracellular diplococci on Gram stain further excludes gonorrhea. **High-Yield:** NAAT (nucleic acid amplification test) is the gold-standard diagnostic test for chlamydia — more sensitive and specific than culture, Gram stain, or antigen detection. A positive chlamydia NAAT with negative gonorrhea NAAT indicates isolated chlamydial infection. ## Treatment of Uncomplicated Chlamydial Cervicitis | Regimen | Indication | Efficacy | Notes | |---------|-----------|----------|-------| | **Doxycycline 100 mg BD × 7 days** | **Chlamydia alone (no gonorrhea)** | **95–98%** | **First-line; oral, convenient** | | Ceftriaxone + Doxycycline | Gonorrhea + chlamydia (dual therapy) | >99% | Overkill if gonorrhea excluded | | Azithromycin 1 g single dose | Pregnancy; doxycycline contraindicated | ~95% | Rising resistance; not preferred | | Ofloxacin 400 mg BD × 5 days | Alternative (if doxycycline contraindicated) | ~95% | Older regimen; less preferred now | **Key Point:** When gonorrhea is excluded by NAAT, doxycycline monotherapy is the first-line, most cost-effective, and guideline-recommended treatment for uncomplicated chlamydial cervicitis. **Clinical Pearl:** The mucopurulent cervical discharge with cervical erythema and friability is typical of chlamydial cervicitis. Unlike gonorrhea (which often presents with thick, greenish-yellow discharge), chlamydia typically causes a more mucopurulent discharge and is often asymptomatic or mildly symptomatic. **Warning:** Do NOT use ceftriaxone if gonorrhea has been ruled out by NAAT — it adds unnecessary cost and IM injection burden without benefit. Ceftriaxone is reserved for confirmed or suspected gonorrhea (especially in dual infections). ## Why Doxycycline Monotherapy Is Appropriate Here 1. **Confirmed chlamydia** (positive NAAT) 2. **Excluded gonorrhea** (negative NAAT) 3. **Doxycycline is first-line** for isolated chlamydial infection 4. **95–98% efficacy** in uncomplicated urogenital chlamydia 5. **Oral, convenient, cost-effective** 6. **Good tissue penetration** (intracellular pathogen) **High-Yield:** Doxycycline achieves high intracellular concentrations, making it ideal for *Chlamydia trachomatis*, which is an obligate intracellular pathogen. ## Partner Notification and Follow-up - Sexual partner(s) within 60 days should be treated with the same regimen - Test of cure is NOT routinely recommended if symptoms resolve (NAAT may remain positive for weeks) - Repeat testing at 3 months is recommended to detect reinfection [cite:CDC STI Treatment Guidelines 2021; Harrison 21e Ch 137]