bioMérieux logo
Talk to an Expert

WOMEN'S HEALTH
Vaginitis

Causes, diagnostic challenges, and how bioMérieux is using its leadership in molecular diagnostics to address them.

What is Vaginitis?

Vaginitis is a common condition that many women will experience at some point in their lives. It refers to inflammation or irritation of the vagina, which can cause symptoms like itching, burning, unusual discharge, and/or general discomfort. These symptoms can be frustrating and even alarming, but vaginitis is usually treatable once the cause is identified.

Causes and Symptoms of Vaginitis

1

Bacterial vaginosis (BV)

Normally, “good” bacteria like Lactobacillus help keep the vagina healthy and slightly acidic. BV is a common vaginal condition that happens when the natural balance of bacteria in the vagina is disrupted, allowing other bacterial species to grow. This can lead to symptoms such as burning, itching, and/or discharge.

2

Yeast infections

Clinically referred to as vulvovaginal candidiasis (VVC), yeast infections are generally caused by Candida species. When the microbiome of the vagina is disrupted, Candida can multiply and lead to symptoms such as thick white discharge and itching.

3

Trichomoniasis

A sexually transmitted infection (STI) caused by Trichomonas vaginalis (TV), can cause frothy, yellow-green discharge and discomfort. TV is often underdiagnosed and may coexist with BV and/or yeast infections. Accurate diagnosis is important, as untreated TV can increase the risk of other viral and non-viral STI transmission (e.g., HIV, HSV) and adverse pregnancy outcomes.

Traditional Methods for Vaginitis Diagnosis

Accurate diagnosis is critical because treatment varies depending on the underlying cause, whether it be BV, VVC, or TV. Traditionally, clinicians have relied on clinical signs and basic tests—such as microscopic examination and vaginal pH measurement—to identify the source of symptoms. While these methods are widely used, they have important limitations.

Bacterial Vaginosis

method description limitations
Amsel Criteria Combines vaginal pH testing, detection of a “fishy” odor with KOH, and identification of “clue cells” under a microscope5
  • Interpretation can be subjective4
  • Requires skilled personnel5
  • May miss co-infections6
  • Can be less accurate than molecular-based techniques7
Gram Stain (Nugent Score) Laboratory-based scoring system using Gram-stained vaginal smears3
Sialidase Enzyme Assay This test detects an enzyme produced by some BV-associated bacteria, including certain Gardnerella strains.21
  • Cannot identify yeast or pathogens responsible for STIs13,14
  • Can lead to incomplete or inaccurate diagnoses and result in delayed treatment

While BV can involve multiple bacterial species, the mere presence—or even relative abundance—of a given bacterium does not inherently indicate dysbiosis. A notable example is the gram-negative bacterium Gardnerella vaginalis. Because Gardnerella is frequently detected in individuals both with and without BV, it is difficult to definitively assign it as a causative agent. Consequently, detection of Gardnerella alone is not a reliable indicator of BV, regardless of the testing methodology, as it may lead to overcalling the condition.28

BV Diagnosis & Treatment for Men

Unfortunately, even after treatment, BV often comes back. However, new research suggests that treating male partners at the same time as women can significantly reduce the chances of BV returning. According to the study , women whose partners were treated had fewer recurrences of BV and stayed symptom-free longer.

Why does this matter?

BV may be linked to bacteria shared between partners, so treating both people can help break the cycle of reinfection. This study supports a new approach that could lead to better long-term outcomes for women dealing with BV.17

Vulvovaginal Candidiasis

VVC is one of the most frequent causes of vaginitis, typically resulting from overgrowth of Candida species. While symptoms like itching and discharge are common, they are not specific—making accurate laboratory confirmation essential.

method description limitations
Microscopy (Wet Mount) Visualization of yeast cells or pseudohyphae in vaginal secretions25
  • Sensitivity is low, especially for non-albicans species24
  • Cannot detect mixed infections without additional testing24
Culture Growth of Candida species on selective media for species identification17
  • Takes time and may not be performed routinely22
  • Cannot detect mixed infections without additional testing24

Trichomoniasis

Trichomoniasis is a sexually transmitted infection caused by the protozoa Trichomonas vaginalis. Often asymptomatic or presenting with nonspecific symptoms, it requires targeted testing to ensure proper diagnosis and treatment.

method description limitations
Microscopy (Wet Mount) Detects motile Trichomonas vaginalis organisms27 Sensitivity declines rapidly after sample collection25
Culture Historically considered the gold standard but rarely used now27 Slow and less practical in routine care18

The Risks of Vaginitis Misdiagnosis

The importance of accurate and timely diagnosis cannot be overstated. Delayed or inappropriate vaginitis treatment is linked to persistent symptoms, high recurrence rates, and serious health consequences, including increased risk of preterm birth and negative effects on intimacy and mental health.4,15

Treating vaginitis without confirming its cause—or using the wrong antimicrobial—can lead to a more than 60% chance of treatment failure and a high likelihood of recurrence.16 These findings highlight the critical need for accurate testing and appropriate therapy to reduce both immediate symptoms and long-term complications.

Molecular Testing for Vaginitis

Recent advances in molecular technology, especially polymerase chain reaction (PCR) testing, have transformed vaginitis diagnosis. Molecular tests can detect multiple microbes at once with greater accuracy and specificity than other traditional methods like microscopy and pH testing.

Most of these tests require sending samples to a laboratory, which delays results compared to near-patient testing modalities. However, there are some molecular tests that can be performed in a practitioner's office, offering more precise diagnoses and timely treatment, reducing the risk of complications, and improving patient care.

Why Clinicians are Choosing PCR for Vaginitis

Fewer Missed Infections

Molecular tests, especially nucleic acid amplification tests (NAATs), offer sensitivities and specificities of over 95% for BV, VVC, and TV. This is a significant improvement over traditional methods like wet mounts, which can miss up to 50% of infections—especially in asymptomatic or low-load cases.18

Clear Answers from a Single Swab

With a single vaginal swab, molecular panels can detect multiple pathogens simultaneously, which is crucial since co-infections are common and symptoms frequently overlap. This helps clinicians avoid misdiagnosis and supports more targeted treatment.19

Consistent Testing Across Settings

Compared to microscopy, which can be influenced by operator technique, molecular tests are typically designed to follow standardized protocols, which may help reduce variability in results.20

molecular vaginitis tests

The Future of Women's Health

Molecular testing for vaginitis is a game-changer. It offers unmatched accuracy reliability, and the ability to detect multiple pathogens at once. While cost and access remain challenges, the long-term benefits are hard to ignore.

While traditional methods remain relevant, ongoing innovation is positioning molecular diagnostics not just as the future of vaginitis testing, but as a cornerstone of advancing women's health.23

bioMérieux: Your Partner in Women's Health

The story of bioMérieux is one of continuous innovation rooted in a simple purpose: to help make the world a healthier place. For over 60 years, we have pioneered and developed diagnostic solutions that deliver crucial information quickly and reliability to support optimal patient care—because every patient, no matter who they are, deserves nothing less.

Our solutions have long advanced women's health, even when not by name, through diagnostics that protect women, mothers, and children across care settings.

Inside the bioMérieux Portfolio

Molecular Testing

Our syndromic panels cover syndromes including bacterial and viral meningitis, infectious gastroenteritis, and respiratory infections.

Microbiology

Our microbiology systems are designed for fast blood culture automation, pathogen identification (ID), and antimicrobial susceptibility testing (AST) to support optimized antimicrobial prescribing for bloodstream infections, including sepsis.

Immunoassays

The VIDAS® 3, immunoassay testing system helps detect hormone dysfunction, early pregnancy, and serious infections in expectant mothers.

Each innovation brings us closer to diagnostics that not only meet women where they are but also pave the way for solutions to tomorrow's health challenges.

bioMérieux Molecular Diagnostics: The Syndromic Approach

bioMérieux has been a leader in molecular diagnostics for over a decade. We pioneered syndromic testing, a breakthrough approach that detects multiple probable pathogens and/or antimicrobial resistance (AMR) genes in a single fast PCR test.

Establishing a Standard in the Lab

The BIOFIRE® FILMARRAY® TORCH System to the forefront, building on our decades-long foundation of microbiology excellence. With a single BIOFIRE® panel, clinicians in acute clinical settings can get accurate, reliable, and comprehensive results on up to seven syndromes in approximately one hour.

Advancing into the Point of Care

bioMérieux has long recognized the need for the same caliber of testing across various syndromes in the near-patient setting. That is why we have brought our proven leadership in syndromic testing to the point of care with the BIOFIRE® SPOTFIRE® System.

We have plans to build upon our foundational respiratory and sore throat testing portfolio with vaginitis and STI tests designed for use at the point of care on our SPOTFIRE platform.*

*These tests are currently under development and subject to change. Not available for sale.

References