To the Editor: I read Geer and Klega’s article on vaginitis with interest.1 This common presentation has diagnostic pitfalls. Bacterial vaginosis, characterized by thin, malodorous discharge, lies at the end of a spectrum of what may be self-limited, temporary shifts in vaginal microflora. Diagnosis requires accurate use of Amsel criteria with wet mount microscopy, Gram stain with Nugent score, or appropriate use of increasingly popular DNA-based tests. The latter are more sensitive and specific but vary in expense, turnaround time, and accuracy, as shown in Table 1.2–4
TABLE 1. DNA-Based Tests for Bacterial Vaginosis
| Test | Manufacturer | Sensitivity | Specificity | Methodology | Estimated reimbursement* |
|---|---|---|---|---|---|
| BD Max Vaginal Panel2 | Becton, Dickinson and Company | 92.8% | 91% | NAAT with real-time PCR | $226–$400 |
| Aptima BV2 | Hologic | 95% | 89.6% | Transcription-mediated amplification NAAT | $88–$223 |
| BD Affirm VPIII3 | Becton, Dickinson and Company | 90% | 67% | DNA probe | $60–$90 |
| NuSwab VG4 | Labcorp | 96.7% | 92.2% | NAAT with real-time PCR | $220–$429 |
| SureSwab BV4 | Quest Diagnostics | 95%–97% | 86%–89% | NAAT with real-time PCR | $189–$373 |
NAAT = nucleic acid amplification test; PCR = polymerase chain reaction.
*—Reimbursement estimates from PayerPrice. Accessed December 1, 2025. https://payerprice.com. Patient charges are typically higher.
More expensive and specific tests may not be reimbursed by insurance, resulting in high out-of-pocket costs for patients. Less specific tests may result in false-positive results, medicalization of normal physiology, and cycles of overtreatment. DNA probe tests for Gardnerella vaginalis may be particularly prone to overdiagnosis.
The BD Affirm VPIII test, for example, is popular due to rapid turnaround and low cost.5 The Centers for Disease Control and Prevention notes that this assay is most useful when combined with vaginal pH measurement and the presence of amine odor.6 G vaginalis is present in 36% to 55% of women without clinical bacterial vaginosis.4
Clinicians may err in diagnosing bacterial vaginosis on the basis of a DNA probe test positive for G vaginalis. Family physicians should recognize that the appropriate diagnosis of bacterial vaginosis is not based solely on the presence of bacteria, but on the presence of ongoing characteristic discharge, ideally verified by pH or whiff testing.
In Reply: We appreciate Dr. Rosenberg’s thoughtful comments highlighting the diagnostic challenges surrounding bacterial vaginosis, particularly the limitations of DNA-based testing.
We agree that bacterial vaginosis lies on a spectrum of microbiome variation and that accurate diagnosis requires correlation of symptoms with objective findings. As noted in the letter, reliance on DNA probe tests, especially those detecting G vaginalis alone, can contribute to overdiagnosis, given the organism’s high prevalence among asymptomatic individuals. Our article emphasizes that Amsel criteria or validated nucleic acid amplification test panels remain the appropriate diagnostic foundations, and that laboratory test results should always be interpreted within the clinical context.1
The important concerns raised about cost variability, potential medicalization of normal physiology, and overtreatment risks reinforce the importance of judicious test selection. In our review, we noted that although multiplex nucleic acid amplification tests demonstrate excellent sensitivity and specificity, their higher cost and variable insurance coverage may limit practicality in certain settings.1 More rapid and inexpensive assays, such as BD Affirm VPIII, should be used with caution and in conjunction with pH and whiff testing, as recommended by the manufacturer and the Centers for Disease Control and Prevention.2,3
We also appreciate Dr. Rosenberg’s detailed comparison of commonly used DNA-based diagnostic tests, including methodology and performance characteristics. These considerations mirror our own guidance that clinicians should balance accuracy, cost, access, and patient impact when selecting diagnostic strategies.
