NEW YORK – Revvity's Euroimmun subsidiary is expanding its fungal disease testing menu with molecular tests to aid the detection of a broader range of pathogens and genetic markers of drug resistances.
The updated slate includes PCR assays that the firm expects to launch this year to aid the identification and treatment of dermatophytosis as well as in-development assays that could aid the treatment of fungal bloodstream and lung infections.
Jackie Weiss, scientific affairs liaison for Euroimmun US, said the firm plans to launch this year in the US an updated version of its EuroArray Dermatomycosis assay, which will be used for the detection of 71 fungal species, mostly dermatophytes, that range from common causes of infections to emerging public health threats such as Trichophyton indotineae. The company also aims to launch in the US during 2025 a PCR-based assay for genetic markers of resistance to terbinafine antifungals among four Trichophyton species. Additionally, Euroimmun plans to soon launch those tests in the EU.
The current version of the EuroArray Dermatomycosis assay is used to detect 56 fungal species with species-level identification of 23 dermatophytes as well as six yeasts and molds.
Further along in the pipeline, the company is developing another PCR-based assay for the detection of Candida auris, which is an emerging cause of healthcare-acquired bloodstream infections, and genetic markers of resistances to first-line treatments. It also has been developing an assay to aid the identification and treatment of infections with Aspergillus species, which can cause mild to severe lung disease.
Euroimmun is expanding its testing menu for fungal infections as public health authorities call for more attention to the risks posed by those infections and the rising prevalence of antifungal resistance.
The World Health Organization published in 2022 a list of priority fungal pathogens that cause invasive acute or subacute systemic infections and are challenging to treat and manage. C. auris and Aspergillus fumigatus are two of the four pathogens in the highest-priority "critical" category along with Cryptococcus neoformans and Candida albicans.
The National Institute of Allergy and Infectious Diseases within the National Institutes of Health also recently accepted applications for grant funding to support the development of diagnostic tests to speed the identification of fungi including Candida species, A. fumigatus, and drug resistance markers for each as well as the detection of Coccidioides species and Mucorales. The agency sought proposals as part of a broader funding package for diagnostics, therapeutics, and vaccines for antimicrobial-resistant bacterial and fungal pathogens as well as antivirals to be used against pathogens with pandemic potential.
Euroimmun's move also follows a de novo market authorization granted to Diasorin in July by the US Food and Drug Administration for a real-time PCR assay for detecting six clades of C. auris. The company said that it was filling a critical gap in molecular testing and positioned the company as the first to commercialize a PCR-based test for C. auris.
As for the need for new dermatophyte tests, Weiss noted that an estimated 20 percent to 25 percent of the global population will develop dermatophytosis during their lifetime. Infections and drug resistances are becoming even more common, with travel and migration fueling the spread of fungal species and inappropriate prescriptions aiding the selection for drug-resistant strains.
Dermatophytosis, or ringworm, is a contagious skin infection that typically develops in an itchy, red ring-shaped rash. Mild infections may clear up within a few weeks while more serious infections may last upward of several months and immunocompromised patients are at risk of more severe infections.
T. indotineae infections, a fungal infection that causes itchy skin, however, cause widespread, inflamed itchy plaques. The multidrug-resistant pathogen has caused an epidemic in southern Asia, and the first US cases were recorded in 2021.
Adam Friedman, chair of dermatology at George Washington School of Medicine and Health Sciences, said that microscopic examination of skin scrapings in a potassium hydroxide (KOH) preparation or stain is used to quickly distinguish between cutaneous dermatophyte infections and other issues that can be similar in appearance such as psoriasis, eczema, or, in rare cases, cutaneous T-cell lymphoma. Distinguishing between species, though, can be more difficult using that method, while antifungal resistances can vary among similar-looking species.
Culture-based testing has similar issues that can hamper its use for treatment selection. He noted that it can be difficult, for example, to distinguish in culture between T. indotineae, which is resistant to terbinafine and susceptible to itraconazole, and T. mentagrophytes, which is sensitive to terbinafine.
Weiss noted that culture also can take days to weeks, it can provide a false negative for patients who have started antifungal treatment, and it can be susceptible to contamination. Any of those issues can lead to delays in diagnosis in comparison with PCR-based testing, she said.
Friedman said that it can be helpful to have PCR-based tests available through clinical labs for the identification of infection causes and drug resistances, especially with the spread of new fungal species and drug-resistant strains. He noted, though, that he doesn't see a huge gap in testing through current testing methods or see a need for PCR testing systems in every dermatologist's office.
Weiss said that, beyond the launch of the tests in the US and EU markets, Euroimmun sees a global need for the tests, particularly in India, where the spread of T. indotineae has become a public health concern.
The dermatophyte tests could be particularly useful in the evaluation of patients who develop infections during or after travel and could have encountered unfamiliar species or strains.
Weiss said that Euroimmun is focused on identifying the clinical need for tests that can help deliver accurate diagnosis of fungal infections, identify resistances, and deliver proper care. She said that the company sees an opportunity to address a need in an area with few available tests.
"If we're able to identify infections, we're better able to control them and prevent the spread, as well," she said.