September 25, 2019

Molecular Diagnosis Delivers Fast, Highly Accurate Vaginitis Testing

Novel diagnostic tools offer women more effective treatment and healing

If you’re a woman who has had vaginitis, you know that getting a fast, accurate diagnosis is the key to effective treatment and relief.  Vaginitis is one of the most common and frustrating health concerns for millions of women around the world—and yet, the diagnosis of vaginitis has historically relied on the use of clinical assessment supported by outdated and often inaccurate microscopic methods.

Collaborative research from Coriell Life Sciences and colleagues validate a growing body of evidence that supports the many benefits of molecular diagnosis of vaginitis over traditional microscopy.  The study—one of the largest comprehensive explorations on diagnostic methods for infectious vaginitis—compared the accuracy of traditional microscopy results for Bacterial Vaginosis (BV) and Candida with newer molecular biology techniques

“Vaginitis can occur when there is an imbalance between harmful bacteria and beneficial bacteria that are normally found in the vaginal microbiome.  Since there are several, different underlying issues that can affect the balance of these bacteria, relying on error-prone microscopy scoring techniques to diagnose vaginitis can leave clinicians unsure of how to treat patients.  A comprehensive and differential diagnostic assay is needed to correctly diagnose the infection and to choose an effective treatment that can reduce the risk of recurrence or more acute outcomes,” said Jeffrey Shaman, Chief Science Officer at Coriell Life Sciences and a research contributor.

Traditionally, the diagnosis of BV requires laboratory examination of vaginal smears by microscopy.  Based on a manual assessment of the bacterial organisms observed, an associated Nugent score is assigned; alternatively, clinical signs can be assessed using the Amsel criteria. Because both methods rely on subjective criteria and are prone to human error, neither can definitively distinguish between BV and other, related infections that require different treatment protocols.

Study data consistently showed that the relatively simple and fast molecular diagnosis method was able to confirm or resolve BV status with higher accuracy than the time-consuming traditional microscopy, and also distinguish between alternative causes of vaginitis. 

The research team deployed an extensive commercial qPCR assay that included tests for BV, Candidiasis, Trichomoniasis, Anaerobic Vaginosis (AV), and STI pathogens.  Polymerase chain reaction (PCR) amplifies and detects DNA and RNA sequences; quantitative PCR (qPCR) is used to detect, characterize, and quantify nucleic acids for numerous applications.  The comprehensive qPCR assay utilized in the study included possibilities for alternative diagnoses, revealing a higher prevalence of Aerobic Vaginitis (AV) pathogens than expected, suggesting AV is likely under-reported at present because reliable tests have not been commercially available.  Since BV treatments are not effective for AV, the researchers recommend including AV in the diagnostic workup for patients seeking medical care for vaginitis. The team also conducted 16S rRNA gene profiling—a fast, inexpensive way to better understand the diversity of bacterial communities—to explore differentiating patterns in the bacterial microflora categorized by the qPCR results.

The research team included participants from Thermo Fisher Scientific; University of Calgary; Division of Microbiology, Calgary Laboratory Services, Calgary; Sexual and Reproductive Health, Alberta Health Services; and the University of Glasgow who joined forces with Coriell Life Sciences to conduct the largest comprehensive study on diagnostic methods for infectious vaginitis to date.  Results of the study, “Molecular diagnosis of vaginitis: comparing qPCR and microbiome profiling approaches to current microscopy scoring,” was published online in the Journal of Clinical Microbiology July 17, 2019.

Related Research:
Diagnosing Bacterial Vaginosis with a Novel, Clinically-Actionable Molecular Diagnostic Tool,”
Journal of Applied Microbiological Research