Rapid test speeds diagnosis of deadly mucormycosis after pandemic surge 

A new lateral-flow test could transform early diagnosis of mucormycosis, a rare but deadly fungal infection that dramatically increased during the COVID-19 pandemic.

Mucormycosis, caused by inhaling spores of Mucorales fungi, was once rare and mainly affected people with weakened immune systems. However, during the pandemic, especially in India, cases of rhino-orbital-cerebral mucormycosis (ROCM), also known as ‘black fungus disease’, surged to over 40,000 cases in just two months, with more than 3,500 deaths. The disease predominantly affects people with poorly managed diabetes, where conditions like high blood sugar and acidosis impair immunity.

The surge was driven by a combination of COVID-19 infection, widespread diabetes, and corticosteroid use for lung inflammation - creating a ‘perfect storm’ that allowed the infection to spread rapidly.

Now, researchers led by Professor Chris Thornton at the University of Exeter’s MRC Centre for Medical Mycology have developed a novel lateral-flow test that detects mucormycosis in just 30 minutes, using patient biofluids. This represents a major improvement over current diagnostic methods, which rely on invasive biopsies and slow lab cultures with limited sensitivity.

Published in the Journal of Clinical Microbiology, the study [1] shows the test is fast, sensitive, and specific. It uses an antibody that binds a unique molecule secreted by Mucorales fungi, providing a clear positive result.

Professor Thornton said:

“Mucormycosis is a devastating disease that spreads quickly and can cause fatal damage and disfigurement. Early diagnosis is vital. Our test offers rapid, effective detection and marks an important step toward commercial availability within three years.”

The test is being developed by ISCA Diagnostics, a University of Exeter spin-out company that previously created a lateral-flow test for another serious fungal disease, invasive pulmonary aspergillosis, now used in over 30 countries.

The study involved collaborators at Besançon University Hospital in France, where the test was validated against patients with mucormycosis, other fungal infections, and controls without infection.

Professor Laurence Millon, Head of Molecular Diagnostics for Invasive Fungal Infections at Besançon University Hospital, said:

“Mucormycosis is notoriously difficult to diagnose, requiring complex lab techniques. This rapid point-of-care test will make diagnosis quicker, cheaper, and more accessible - especially in countries with limited diagnostic facilities.”

More information online

1. Detection of Mucorales antigen in bronchoalveolar lavage samples using a newly developed lateral-flow device’ published in the Journal of Clinical Microbiology.