New test could speed detection of three serious regional fungal infections
Certain serious fungal infections occur in regions of the United States with specific environments and are often tied to soil exposure. These infections can affect both healthy and immunocompromised people, but proper diagnosis remains slow, which delays treatment.
The current gold standard for making a diagnosis relies on fungal culturing, which can take weeks, and tests that look for antigens, which lack specificity, or antibodies in the blood, which are often unreliable in early disease. But now researchers from Indiana University Health and the IU School of Medicine have developed a new molecular test capable of detecting three major pathogenic fungi at once-and with a much quicker turnaround than traditional methods.
The work will be presented at the Association for Molecular Pathology (AMP) 2025 Annual Meeting & Expo, taking place Nov. 11–15 in Boston.
Dr. Kenneth Gavina, Ph.D., is the director of clinical microbiology at Eskanazi Health in Indianapolis. He oversaw the project through the Indiana University School of Medicine. His team sought to identify three fungal infections that affect thousands of people each year, are often mistaken for other respiratory illnesses, and can be life-threatening, particularly in immunocompromised people:
- Histoplasmosis usually presents as lung infection in patients who’ve inhaled soil containing bird or bat droppings. It’s most common in the Ohio and Mississippi River valleys.
- Blastomycosis presents as a lung infection too but also can progress to affect skin, bones and other organs. It occurs mainly in the central and southeastern U.S.
- Coccidioidomycosis is commonly known as Valley fever. Though most of these lung infections are mild, some patients develop severe pneumonia or experience infection elsewhere in the body. It occurs primarily in southwestern states, including Arizona, California and New Mexico.
The researchers designed a multiplex real-time PCR test, which means it can detect multiple pathogens simultaneously from the same sample.
Their test targeted three genetic regions that are unique to each fungus: ITS1 for Histoplasma, BAD1 for Blastomyces, and A2/PRA gene for Coccidioides. By detecting the fungi’s genetic material directly, the PCR test bypasses the slow culture process that is complicated by the fungi’s ability to switch between environmental and human forms.
When they compared their PCR results to standard lab methods, the PCR test identified all tested samples with 100% accuracy. In addition, it was 100% specific, meaning it didn’t mistakenly detect other fungi or contaminants.
The workflow also eliminates the need for time-consuming DNA-extraction steps, potentially reducing turnaround time and laboratory risk associated with handling live pathogenic fungi.
“Our assay has the potential to significantly improve turnaround time and diagnostic confidence for infections that have historically been difficult to detect quickly,” Gavina said.
Importantly, the team’s system runs on a platform already used in many clinical laboratories, making it potentially quite accessible.
“While additional clinical validation is under way, this assay shows strong potential to fill a major gap in fungal diagnostics,” Gavina said. The assay has the ability to detect the three major causes of endemic mycoses in the United States directly from clinical specimens or be used as a form of definitive identification from fungal culture. “Clinicians currently have no FDA-approved molecular tests for these three pathogens, making rapid, reliable detection a pressing need.”
Reference:
New test could speed detection of three serious regional fungal infections, Association for Molecular Pathology, Meeting: Association for Molecular Pathology 2025 Annual Meeting & Expo.
