What Is Mucormycosis Or 'Black Fungus' And Why Is It Affecting So Many Covid-19 Patients?

Dr Nikhil Tandon, Professor and Head, Department of Endocrinology and Metabolism, AIIMS, New Delhi, explains what is causing a sudden surge in mucormycosis in Covid patients, and how we can prevent and treat it effectively.

What is Mucormycosis and why is it affecting so many Covid-19 patients?

Mucormycosis is a fungal disorder. Fungi are present extensively in our environment. If mucormycete spores enters the nostrils of a healthy human being, the body¡¯s immunity fights off the infection and does not let the disease happen. But in people with compromised immunity, these spores, transform in to hyphae, invade and cause the disease. Prior to the COVID epidemic, the mucormycosis infection was observed in patients with uncontrolled diabetes, especially in an acute condition called diabetes ketoacidosis, cancer patients,especially in those on chemotherapy, and individuals with HIV disease among others.

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The current wave of mucormycosis, however, seems to be directly related to Covid-19 and is widely affecting people who have Covid or are recovering from it.

Three reasons that may have contributed to this sudden surge of mucormycosis cases are i) a large number of Covid-19 patients in a small duration of time, ii) new variants of SARS-Cov-2, and iii) concurrently uncontrolled diabetes in these Covid patients

Early data from AIIMS suggest that a significant number of patients currently being diagnosed with mucormycosis had uncontrolled diabetes. Over and above this, we have seen a significant increase in the use and misuse of steroid. Steroids though a preferred treatment for moderate to severe Covid-19 patients, have to be given at a specific time, for a pre-defined duration, and in pre-defined doses. Injudicious use of steroids, including by self-medication can do more harm than good. All these factors have led to the recent surge in the mucormycosis cases.

Why is it called black fungus? How damaging it could be?

Black Fungus is a term given by people. Mucoromycetes is not black coloured fungus. It is an invasive fungus; it invades smaller and bigger blood vessels, diminishes the blood supply to the tissues and kills them. The dead tissue looks black in colour.

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Mucormycosis , if not detected and treated, is potentially damaging. In immuno-suppressant individuals, it can cause lots of morbidity. For example, if it travels from the nose and sinuses towards the eye, it can damage the vision. If it travels into the brain, it could be fatal.

How to prevent mucormycosis in Covid patients?

This fungus is present almost everywhere so, it is difficult to completely avoid the exposure. However, one can limit it by avoiding going to damp and humid places, farms, and dusty construction sites.

Further, one should take all the precautions to protect oneself from catching Covid. Follow Covid-Appropriate Behaviour: wear masks, wash hands, avoid crowds, maintain physical distancing, and take the vaccine. If a person has diabetes, they must do everything to keep it under control.

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Another important point that we tend to forget is any infection can lead to an increase in blood sugar levels. Besides, steroids also can cause an increase in blood sugar levels.This aspect must be kept in mind by the patient and the treating team ¨C periodic screening for blood sugar must be done in all patients with COVID, so that early treatment can be initiated as soon as the blood sugar shows a tendency to rise.

How do we treat mucormycosis?

Most cases of mucormycosis are treatable. And if we detect them early, the damage can be controlled. Drug Amphotericin B is highly effective.Its liposomal version allows doctors to give adequate doses over a relatively shorter duration than possible with conventional preparations of this drug, thereby helping control the infection early.

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There are two other preparations: Posaconazole, which we have used as a stepdown drug after we control the infection with amphotericin; and Isavuconazole. The latter is a relatively newer drug, but initial information suggest that it is also a promising agent for treating mucormycosis.

Along with medications, surgical removal of the dead tissue is also strongly advocated.