The potential for rapid antigen testing for mucormycosis in the context of COVID-19

ABSTRACT

Introduction

Mucormycosis is a highly aggressive angio-invasive disease of humans caused by Mucorales fungi. Prior to the COVID-19 pandemic, mucormycosis was a rare mycosis typically seen in immunocompromised patients with hematological malignancies or in transplant recipients. During the second wave of the pandemic, there was a dramatic increase in the disease, especially in India where a unique set of circumstances led to large numbers of life-threatening and disfiguring rhino-orbital-cerebral mucormycosis (ROCM) infections.

Areas covered

The review examines mucormycosis as a super-infection of COVID-19 patients, and the risk factors for COVID-19-associated mucormycosis (CAM) that drove the ROCM epidemic in India. The limitations of current diagnostic procedures are identified, and the measures needed to improve the speed and accuracy of detection discussed.

Expert opinion

Despite increased awareness, global healthcare systems remain unprepared for further outbreaks of ROCM. Current diagnosis of the disease is slow and inaccurate, negatively impacting on patient survival. This is most evident in low- to middle-income countries which lack suitably equipped diagnostic facilities for rapid identification of the infecting pathogens. Rapid antigen testing using point-of-care lateral-flow assays could potentially have aided in the quick and accurate diagnosis of the disease, allowing earlier intervention with surgery and Mucorales-active antifungal drugs.

KEYWORDS:

• Mucorales
• Rhino-orbital-cerebral mucormycosis (ROCM)
• COVID-19-associated mucormycosis (CAM)
• rapid antigen test
• Point-of-care test (POCT)
• lateral-flow technology

Article highlights

• Mucormycosis is the second-most common mold disease of humans after invasive aspergillosis, with life-threatening infections typically seen in immunocompromised patients.

• The second wave of the COVID-19 pandemic saw a dramatic increase in mucormycosis as a super-infection especially in India where uncontrolled diabetes and indiscriminate use of corticosteroids contributed to an epidemic of life-threatening rhino-orbital-cerebral infections.

• The paucity of rapid, accurate, and sensitive tests for the disease, especially in low- to middle-income countries, contributed to the high rates of mortality and morbidity in patients with COVID-19-associated mucormycosis (CAM).

• Rapid antigen testing using lateral-flow technology may have enabled point-of-care detection of rhino-orbital-cerebral mucormycosis (ROCM) in resource-limited settings.

• A lateral-flow test that incorporates a monoclonal antibody specific to Rhizopus arrhizus, the principal global agent of ROCM, has been developed that could be rapidly deployed as a POCT for the disease.

Declaration of interest

The author is affiliated with ISCA Diagnostics Limited.

Additional information

Funding

This paper was not funded.