Should I test for Chlamydia (sexually transmitted infection) and Gonorrhea (Neisseria gonorrhoeae infection) if a wet prep is positive for clue cells indicating Bacterial Vaginosis (BV)?

Testing for Chlamydia and Gonorrhea in Bacterial Vaginosis

Yes, you should test for chlamydia and gonorrhea when clue cells are present on wet prep, particularly in sexually active women under 25 years or those with STI risk factors, because these infections frequently coexist and can cause serious complications like pelvic inflammatory disease even when asymptomatic. 1

Rationale for Concurrent Testing

The presence of clue cells indicates bacterial vaginosis (BV), but this finding alone does not rule out concurrent sexually transmitted infections. The CDC explicitly recommends that all patients tested for gonorrhea should be tested for other STDs, including chlamydia, syphilis, and HIV 1. This recommendation is based on:

• High coinfection rates: Patients with one vaginal infection frequently harbor multiple pathogens, though true coinfections with BV and STIs occur in less than 1% of cases 2
• Asymptomatic presentation: Both chlamydia and gonorrhea are frequently asymptomatic in women, yet can progress to PID, tubal scarring, infertility, and ectopic pregnancy 1
• Overlapping risk populations: Women presenting with vaginal symptoms often have risk factors for both BV and STIs 1

Risk-Based Testing Algorithm

Test for Chlamydia and Gonorrhea if:

• Age <25 years and sexually active - This is the highest risk group with mandatory annual screening recommended 1, 3
• Age ≥25 years with risk factors: new or multiple sex partners, inconsistent condom use, previous STI, partner with STI, commercial sex work, or drug use 1
• High-prevalence settings: STD clinics, certain geographic areas, or communities with elevated infection rates 1
• Uncertain follow-up: If the patient is unlikely to return for results 1

Consider Deferring Testing if:

• Low-risk patient: Age ≥25 years, mutually monogamous relationship, no STI risk factors, and reliable follow-up expected 1
• Recent negative screening: Within the screening interval for low-risk patients 1

Testing Methodology

Use nucleic acid amplification tests (NAATs) as the preferred diagnostic method 1, 3:

• Sensitivity: 86.1-100% for both chlamydia and gonorrhea 3
• Specificity: 97.1-100% 3
• Can use the same specimen (cervical swab, vaginal swab, or urine) to test for both pathogens 1
• Self-collected vaginal swabs are acceptable and FDA-cleared 1

Critical Clinical Pitfall

Do not assume BV explains all vaginal symptoms. While clue cells are highly specific for BV (94.3% specificity, 98.2% sensitivity) 4, this diagnosis does not exclude STIs. The CDC notes that trichomoniasis, chlamydia, gonorrhea, and BV are the most commonly diagnosed infections in women with vaginal complaints 1. Testing only for BV risks missing serious infections that require different treatment and partner notification.

Treatment Considerations

• If testing is performed: Await results before treating for chlamydia/gonorrhea unless the patient is high-risk or unlikely to return 1
• In high-prevalence settings (>5% gonorrhea prevalence): Consider presumptive treatment with azithromycin 1g orally or doxycycline 100mg twice daily for 7 days before results are available 3
• Treat BV concurrently: The presence of clue cells warrants BV treatment regardless of STI testing 1

Partner Management

If chlamydia or gonorrhea is diagnosed, all sex partners from the past 60 days must be notified, examined, and treated 3. Both patient and partners must abstain from intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen 3. Retest at 3 months to detect reinfection 3.

Special Populations

Pregnant women: Screen at first prenatal visit and third trimester; treat with azithromycin or amoxicillin if positive 3. The stakes are higher given risk of vertical transmission and pregnancy complications.