Several news headlines for over a month have read like "cases of mucormycosis or black fungus". In fact, many ministers too have been equating mucormycosis with black fungus as the infection surged during the second wave of COVID-19. For example, Maharashtra Chief Minister Uddhav Thackeray recently tweeted, "The State has around 3,000 patients with mucormycosis or black fungus."

But are the terms interchangeable? According to experts, calling mucormycosis 'Black Fungus' is a misnomer because the infection is not a recent phenomenon.

FactChecker spoke to Dr Manish Munjal, an ENT specialist at Sir Ganga Ram Hospital in New Delhi, and Dr Ishwar Gilada, an infectious diseases expert, president of the AIDS Society of India and governing council member of International AIDS Society, to understand the difference between the two fungal diseases.

What is Mucormycosis?

Mucormycosis, previously called zygomycosis, is rare and invasive and a non-fungal infection caused by a group of molds called mucormycetes. These molds live throughout the environment and enter the body through nasal passages.

"Mucormycosis is an opportunistic fungal infection. It happens when there is a compromised host immunity. Earlier, it used to infect people with HIV, cancer and those who had a liver transplant but it was quite infrequent; around two or three cases in a big hospital like Gangaram in a month. It was still deadly but we had the means to treat them. But it wasn't as high in density as it is currently," Dr Munjal told FactChecker.

What is the difference between Mucormycosis and Black Fungus?

According to both the doctors, the main difference is in the actual colour of the fungus and the colour of the tissue.

"Mucormycosis is not actually black. The fungus does not derive its name from the colour of its filaments which is the fungi itself but due to the blackening it causes on the host body it infects. The tissue becomes dark and then the skin inside the nose or the scab that forms is almost black in colour," said Dr Munjal.

"In medieval times, people associated the bubonic plague with Black Death. The colour of the tissue governed the name of the disease. So, when we say yellow fever, the virus is not yellow. It's the colour of the pigment, not the virus," he added.

It is neither a new disease and nor does the fungus have a colour when looked at through a microscopic lens. It's the dead tissue that turns black.

"There are fungi of different colours. For example, candida is white. Similarly, there are brown, grey, black, orange and yellow fungi. But the colour of mucormycosis is not black. The term which is being currently used is a misnomer," said Dr Gilada.

"It's better to call it mucor. It's called black fungus because it is caused in the nasal area where an ulcer is formed. Later, the ulcer becomes necros or a dead tissue which is black in colour. Hence, it's called black fungus but the fungus is not black in colour, it's the skin that becomes black. Under the microscope, mucormycosis does not really have a colour," explained the infectious diseases expert.

In fact, AIIMS Director Randeep Guleria, in a press conference on May 24, 2021, asked the media to refrain from labelling the fungus with different colours as it could create confusion. "Black fungus is another family; this term got associated with mucormycosis due to the presence of black dots among the culture of white fungal colonies. In general, there are various types of fungal infections such as candida, aspergillosis, cryptococcus, histoplasmosis and coccidioidomycosis. Mucormycosis, candida and aspergillus are the ones observed more in those with low immunity," said Dr Guleria at the press briefing.

Dr SP Kalantri, Professor of Medicine at the Mahatma Gandhi Institute of Medical Sciences and Medical Superintendent of Kasturba Hospital, Sevagram, also highlighted how both terms are not the same. He tweeted, "The fungus is not black. The tissues it destroys turn black."

Before the second wave, COVID-19-associated invasive fungal infections were also reported during April 2020 in India. These infections have also been reported during previous epidemics such as SARS in 2003.

Mucormycosis is lethal and is fatal for people whose immune system is already low. Deaths due to the fungal infection in previous coronavirus outbreaks such as SARS ranged from 25% to 73%. But this infection is not a recent phenomenon.

"All our knowledge that we have employed in treating COVID patients with mucormycosis stems from the experience of treating the same infection in the past. The antifungal infections in the market are from mucormycosis only," said infectious diseases expert Dr Gilada.

Although technically incorrect, experts believe the correlation between the infection and the colour has resulted in more awareness and early treatment of patients. When asked if associating fungal infections with colour codes is incorrect, Dr Munjal said, "Medically it should be avoided, but it has also been a great tool in educating people. Many have been able to reach centers fast and have led to people getting themselves treated at a much higher rate as compared to before. I am happy to say that some have been treated within a week which was almost unheard of previously. That is because they could associate the symptoms with the black word. If you give medical jargon to it, it might not be able to catch the imagination of the public."

While highlighting who are more at risk against the disease, the experts said the vulnerable section are the ones who have diabetes.

"These COVID patients were given steroids, antibiotics and because of this, their sugar levels were high and were untreated for a long time. They were in isolation centres and hospitals. This is when the fungus got a chance to enter the nasal oxygen cannulas, pipes, and contaminated hands. This is still worrisome and if there ever is a third wave we must make sure it does not happen again," warned Dr Munjal.

Why the Surge of Mucormycosis Cases During Second Wave?

There are 19,727 active cases of mucormycosis across the country, according to an affidavit filed by Deputy Drugs Controller Rubina Bose of Central Drugs Standard Control Organisation on behalf of the central government in Bombay High Court on June 2, 2021.

Increase in symptomatic patients, use of steroids and people needing help of oxygen cylinders were cases behind the surge in cases.

"In the second wave, there were more symptomatic patients than the first wave, so more people were hospitalised. Steroids were used in more people too, especially for those with diabetes which reduced their immunity significantly. When the immunity goes down the body immediately catches bacteria, fungus or parasite," said Dr Gilada.

"More people needed oxygen in the second wave and oxygen goes through a tube which goes to a bottle which uses water. It's called a humidifier. The water or the tube can be the source of fungus. Suppose we keep food outside for three or four days, it catches fungus. We can say that the body is like a sack of sugar which the fungus is attracted to," he explained.


In terms of COVID-19 management, doctors should be very careful in scrutinising the stage of the infection. Nothing should be done to decrease the immunity of the person, Munjal said. The experts listed the following practices that can help prevent people from getting the infection:

1.Antibiotics, steroids and antiviral drugs should not be used unnecessarily. Suppose the patient is losing oxygen or the fever refuses to go down after eight or nine days, doctors should carefully evaluate such patients and administer steroids under a monitored dosage system.

2.Sugar levels should be carefully monitored as well so that the immune system does not weaken.

3.There should be extra effort in maintaining hygiene. A nose saline spray and mouthwash should be kept handy.

4. Hospital and home equipment used to administer the nasal cannulas, oxygen moisturizing systems should be totally sterilised.