Faster, More Accurate Testing for BV and Candida

Roche’s cobas® BV/CV assay aims to improve the diagnosis and management of BV and CV—the two most common causes of vaginal infections. It is now available in all countries accepting the CE mark.

By accurately identifying the infection in a single test, this new PCR duplex assay will also support clinicians to make more targeted treatment decisions and help reduce the burden of recurring symptoms for millions of women worldwide.

Vaginal infections are among the most common reasons for gynaecological consultations. In fact, BV impacts ~25% of women of reproductive age, while up to 75% of women experience CV—also known as thrush—at least once in their lifetime.

Yet current diagnosis often relies on microscopy, pH testing, and clinical observation, which can be inaccurate and lead to delayed or unsuitable treatment and serious complications for some women. The cobas® BV/CV assay resolves this challenge by delivering accurate and specific results, allowing healthcare professionals to deliver targeted therapies to patients more quickly.

Roche offers instruments with different throughput for this test, and first results can be obtained in less than three hours, compared with up to days for traditional methods such as cultures.

The new PCR duplex assay simultaneously and specifically detects the leading infectious causes of BV and/or CV. This provides a faster and differentiated diagnosis using a single vaginal swab that can also be used for broader sexual health testing with the on-market PCR duplex assays cobas CT/NG (Chlamydia trachomatis/Neisseria gonorrhoeae) and cobas TV/MG, (Trichomonas vaginalis/Mycoplasma genitalium), eliminating the need for additional samples for extended testing.

Molecular tests can significantly improve diagnostic precision compared to in-clinic microscopy and Amsel's criteria, which are subjective and user-dependent. Also, physicians often have no or limited access to a microscope and/or training to perform traditional diagnosis.

The cobas BV/CV test differentiates between the conditions, which have overlapping, non-specific symptoms, by detecting the specific bacteria associated with BV and the yeast associated with CV. BV/CV co-infections are also common (estimated in 20–30% of cases). These infections cause uncomfortable and sometimes distressing symptoms such as itching, burning, discharge, and irritation, and they are also associated with an increased risk of having a sexually transmitted infection (STI).

Our test has high analytical sensitivity and specificity, which—when combined with fast turnaround time—provides rapid, accurate results to support earlier, more confident diagnosis at the point of care or in the laboratory.

Unlike the subjective Amsel's criteria or Nugent scoring for Gram stain, our molecular BV assays use an algorithm developed by our Research and Assay Development teams. This algorithm detects specific DNA targets associated with BV-related bacteria, for example, Gardnerella vaginalis, Atopobium vaginae, and other BV-associated bacteria, and integrates the data from these multiple bacterial markers to make the final qualitative result.

The algorithm also accounts for the relative presence of the “good”, protective bacteria Lactobacillus spp. A. vaginae is considered to be the most harmful species, and the presence of this bacterium could be a positive or a negative result, depending on the concentration of Lactobacillus. This provides a more robust, reproducible, and objective assessment of the shift in the vaginal microbiome that characterizes BV.

For the detection of CV, there is a Ct-value cutoff that discriminates between background and clinical infection in the symptomatic patient. The Ct-value cutoff was determined internally and validated in a clinical study.

Our test also supports better antimicrobial stewardship by enabling more targeted therapy rather than broad empirical prescribing, helping reduce unnecessary antibiotic use.

The traditional diagnostics are the Amsel criteria and Nugent scoring, which are a combination of microscopy and clinical parameters, and they are subjective. There are other commercially available nucleic acid amplification tests (NAATs) for BV (e.g., BDMax Vaginal Panel, Aptima BV, and Xpert Xpress MVP).

In our clinical trial, the cobas BV/CV assay was compared to a composite reference standard of the three commercially available BV NAATs (BDMax Vaginal Panel, Aptima BV, and Xpert MVP). We believe that using three BV NAATs as comparator tests is an optimal approach to compare how cobas BV/CV performs in the detection of BV, as it provides a more robust analysis by minimizing the biases and weaknesses of each comparator NAAT.

For CV, the cobas BV/CV assay was also compared to two composite reference standards. The first comparison analysis compared it to the traditional gold standard of culture/MALDI-TOF. The second comparison compared the CV results to three commercially available CV NAATs, which are increasingly used.

The test will help improve diagnostic accuracy for millions of women affected by vaginitis annually, addressing a major unmet need by improving women’s health outcomes.

A more precise diagnosis protects women from the risks of delayed or incorrect treatment, leading to faster relief from symptoms and a reduction in recurrent infections, discomfort, and anxiety. It limits the impact of vaginal conditions on quality of life and daily activities.

This new test has higher analytical sensitivity and specificity than traditional in-clinic testing and culture, which leads to a faster, more accurate, and objective diagnosis (often available in under 24 hours, depending on the lab) compared to cultures, which can take days. This reduces the high rate of misdiagnosis or missed co-infections common with microscopy.

Symptoms of BV, CV, and TV often overlap: Up to 30% of patients may have a BV/CV co-infection and up to 80% a BV/TV co-infection. Molecular panels (especially multiplex panels that include BV, CV, and TV) can simultaneously detect all relevant pathogens from a single swab.

This greatly improves diagnostic accuracy for mixed infections and means all bacteria present can be treated in one course, which helps prevent treatment failure or recurrence.

Infectious diseases are one of the most significant causes of mortality worldwide, accounting for more than 13 million deaths in 2019. According to the World Health Organization, 6 out of 10 threats to global health in 2019 were related to infectious diseases, and they were ranked third in terms of deaths behind heart diseases and cancer. Without timely intervention and preventative measures, they can spread rapidly with potentially catastrophic effects.

Diagnostics help people live better, longer, and healthier lives. But our growing and aging global population means clinical laboratories are having to do more with less. Our patient-centric approach is focused on expanding our extensive portfolio of trusted and flexible infectious disease diagnostics.

We’re also committed to improving women’s health with a range of solutions and diagnostic tests to help assess risk, identify disease, and monitor patients with specific solutions aimed at meeting the unique needs of women at every stage of life.

We have diagnostic solutions, including high medical value tests, for fertility and pregnancy, polycystic ovarian syndrome, prenatal testing, menopause, bone health, and for breast, ovarian, cervical, and endometrial cancers.

We deliver innovations that give healthcare professionals the tools and confidence they need to support quality care for women, meeting or setting new standards for clinical guideline recommendations.

Innovations such as the cobas® BV/CV assay reinforce our broader strategy to close persistent women’s health diagnostic gaps, supporting more accurate, earlier answers for common yet under-recognised conditions and helping healthcare services deliver more efficient, patient-centred care at scale.