What is ‘black fungus’ found in India’s COVID patients?

The images of patients with “black fungus” are truly shocking. An infection will often start in the sinuses or lungs and spread to bones and other tissue in the body. In the worst cases, a black fungus infection can attack the eyes and brain. It can be fatal.

After an operation to stop an infection, patients’ faces often appear as if mutilated or totally disfigured. DW has decided not to publish such images as they can be distressing.

But the fact is that doctors in India are diagnosing the black fungus — known medically as mucormycosis — more and more in COVID-19 patients.

Patients with a weakened immune system are at higher risk of contracting mucormycosis. That includes patients who have just recovered from a COVID-19 infection.

Mucormycosis is a rare infection. People contract it when they come into contact with mucormycetes, a type of mold.

Right now, in India, with the country fighting an intense wave of SARS-CoV-2 , patients are having to suffer this as well.

The situation is very serious, says Oliver Cornely, a professor for translational research at the European Excellence Center for Invasive Fungal Infections in Cologne, Germany.

“Doctors in India are reporting that the number of cases of mucormycosis has risen sharply and that the larger hospitals are diagnosing it in patients every second day,” says Cornely.

It’s especially those patients who have had a COVID-19 infection, even those who have recovered, who are contracting the fungus. The exact number of cases is, however, currently unclear.

Like a horror movie

The mold mostly infects surface areas of the body, such as the skin. But it also infects inner parts of the body that come into contact with air. When people inhale the fungal spores, the spores enter the sinuses and spread to airways deeper in the body.

“The fungus starts in the sinuses and spreads through mucous membrane into the bones,” explains Cornely. “It can also proceed through the bones to the eyes, eye socket, muscles and nerves.”  

When that happens, surgeons often have to remove an entire eye to save a patient’s life. It’s a radical operation, but seen as the only way for doctors to remove infected tissue.

“The fungus can also infect the brain,” says Cornely.

When that happens, it’s almost always fatal. It depends on how fast and how well the patient receives treatment. The death rate lies between 50-90%.

Almost unstoppable

Initial symptoms are often quite common-looking: Red eyes or a reddened nose.

Later, patients may have bloody or black nasal discharge, perhaps also a fever and may experience difficulty breathing.

It’s important to treat a mucormycosis as early as possible. But doctors are often slow to recognize the symptoms and infection, and take appropriate measures.

“There’s no doubt that the doctors in India are experienced enough to spot a mucormycosis, but even they wouldn’t normally see such infections that frequently, like every day or every other day,” says Cornely. But that is precisely the situation they face now, he adds. 

In most cases, the only way to stop an infection is through a surgical procedure. Some patients come out the other side looking disfigured.

“If the infection has spread from the sinuses into the eyes, surgeons may have to remove parts of the face,” says Cornely. “The mucor destroys all the tissue that it finds in its way. That includes blood vessels, and that means that any medication will not be transported to where it’s needed in the body.”

So, an operation is usually the only way to go.

High-risk group: People with diabetes

Diabetes patients are a risk group, and in India the number of people with diabetes is high. Diabetes is sometimes described as its own epidemic there, says Cornely.

“Particularly at risk are those people who have diabetes, but who have never been treated for it,” he says.

Their immune system is weakened. And among those diabetics, whose condition has never been treated, the mucous membrane can produce a molecule that even acts as a receptor for the fungal spores.

“That’s how the spores attach themselves to the body, and as soon as they have done that, they start to grow and build a threadlike fungus,” continues Cornely.

First corona, then a fungal infection

COVID-19 patients are at risk because their immune system is already weakened.

That may be contributing to the rise in cases of mucormycosis in India.

But at the same time, there is the effect of cortisone. Cortisone inhibits infections but it also restricts the immune system, making things easier again for mucor spores.

Once they are in the body and the fungus has started to spread, the prognosis for patients is bad. So, what’s good for the one infection, opens a door for the other.

“A patient’s airways will often become sore through a corona infection,” says Cornely. “The epithelial tissues, which would normally form a defense, are destroyed.”

That’s an ideal situation for the black fungus.

“These fungi don’t really belong in people. Their ecological duty, as it were, is to degrade wood, plants and other dead bodies,” says Cornely.

It usually lives in soil but can also be found in rotting food, such as fruit.

But why so many cases in India?

“It’s possible,” speculates Cornely, “that it has something to do with the different climate in South Asia, that it’s different from Germany, where the fungus usually only affects one or two people in a million per year.”

He says it’s also possible that people in India are subject to a higher level of the pathogen. Hygiene standards may be lower, he says, poverty and cramped living conditions may also play a role.

All such aspects can make it easier for disease to spread.

“It’s through COVID-19,” says Cornely, “that illnesses that are otherwise rare are coming more to the fore now, and mucormycosis is just one of them.”