A rare black fungus is infecting many of India's COVID-19 patients—why?

Indiscriminate steroid usage and high blood sugar levels are potentially responsible for driving an uptick in a rare fungal infection among vulnerable COVID-19 patients.

On May 9, Ananyaa Mazumdar received a call that left her stumped. Her panic-stricken cousin explained that her 48-year-old aunt, who had recently recovered from a COVID-19 infection, had lost most of her vision in both eyes.

The emergency room doctors at the Max Super Speciality Hospital in Ghaziabad, a satellite city outside India’s capital New Delhi, suggested that because the infection was so advanced, she needed immediate surgery to remove her eyes. Aghast at first, the family soon realized that they had no other option.

“It’s all that could be done—and had to be done,” Mazumdar said. “It’s like we were sitting on a ticking time bomb.”

Her diabetic aunt was diagnosed with an extremely rare fungal infection called mucormycosis that’s on the rise among recovering and recovered-but-vulnerable COVID-19 patients in India. Colloquially referred to as “black fungus” due to its dark pigmentation, this potentially fatal infection starts in the nose and spreads to the eyes and then the brain.

Public health experts are blaming the indiscriminate use of steroids to treat COVID-19 as the likely cause. Steroids reduce inflammation in the lungs. But overuse of these drugs in COVID-19 patients can result in lowered immunity and raised blood sugar levels. These conditions leave some patients, particularly those with uncontrolled diabetes, susceptible to such infections.

As India—the diabetes capital of the world—continues to battle a devastating second wave of COVID-19, ear, nose and throat physicians are expecting to see more mucormycosis cases come their way in the next few weeks.

In Delhi, for instance, Manish Munjal, an ENT surgeon at Sir Ganga Ram Hospital, has been treating nearly 15 new cases every day since last week. According to him, the city has recorded about 250 mucormycosis cases since April.

“That’s a huge number,” he says, comparing it to a case or two he’d treat every month in pre-pandemic times.

In the western Indian state of Maharashtra, which has been hit hardest by COVID-19, state health minister Rajesh Tope said there could be more than 2,000 mucormycosis patients. In the neighboring state of Gujarat, some 300 cases have been reported from four cities.

“The concern is that this is just the start,” Munjal says. “The infection typically begins to hit the body two to three weeks into the steroid therapy, and we might see the case numbers jump in the coming weeks.”

What is the black fungus?

Mucormycosis is an invasive infection caused by a class of molds called mucormycetes. These fungi are ubiquitous, naturally occurring in our environment, most commonly in soil. Humans get the infection by inhaling the fungal spores floating around in the air and in dust. These spores get lodged in the nasal passages and sinuses and cause disease at that site.

But not everyone exposed to the spores will get the infection. “For most part, if you have a normal immune system, it’s an asymptomatic, silent encounter,” says Tobias Hohl, chief of infectious disease service at New York’s Memorial Sloan Kettering Cancer Center. But developing the invasive disease depends on a person’s health condition.

People with compromised immune systems, for example, those with blood cancer undergoing chemotherapy or bone-marrow transplant patients who can’t form neutrophils—a type of white blood cell that defends against infections—in the initial weeks, may fall victim to mucormycosis.

Similarly, during COVID-19, patients prescribed heavy and prolonged steroid doses can have weakened immune systems. “We’ve seen people go crazy with steroid prescriptions,” says Lancelot Pinto, a pulmonologist at Mumbai’s P.D. Hinduja Hospital and Medical Research Center. “There’s a misperception among doctors that more severe the [COVID-19] case, higher the dose of steroids needed, which isn’t supported by any trial so far.”

Steroids can cause blood sugar levels to spike, which can be especially challenging for patients with uncontrolled diabetes. Higher blood sugar levels and more acidic blood creates a fertile environment for Mucorales fungi to thrive.

In such vulnerable patients, the spores germinate to form long tubular filaments that can grow into the sinuses, into the bone, and the blood stream. The symptoms of mucormycosis and progression of the infection can vary from person to person; they include a throbbing headache, fever, facial and nasal pain, blackish nasal discharge, loss of vision, toothache, loosening of teeth, swelling in the upper jaw, and sometimes face paralysis.

“This is a horrific infection, and can be disfiguring,” Hohl says. “Unless treated, the infection can cross into the central nervous system, and that’s more dangerous.” The chances of dying exceeds 50 percent if the infection reaches the brain.

Early diagnosis can be lifesaving. But the infections can be extremely challenging to treat, even at an early stage.

Treating mucormycosis

Patients are prescribed antifungal treatments such as liposomal amphotericin B injections for at least 10 days to several weeks after diagnosis. But these essential drugs have the potential to induce substantial side-effects, including kidney damage.

Often, a surgical intervention is also needed. In less severe cases doctors insert an endoscope through the nasal cavity and remove any diseased tissue. If the infection has spread further, the surgeons may need to remove the eyes or the jaw bone.

At the Samadhan Dental Super Specialty Center in Dhule, Maharashtra, oral and maxillofacial surgeons Rajesh and Shrenik Oswal have since April treated nearly 50 former COVID-19 patients with mucormycosis of the jaw, 25 of whom have had their jaw fully or partially removed to stop the disease spread.

Ajinkya Kelkar, an ENT surgeon in Pune city’s Maharashtra Medical Foundation Hospitals, has recently treated a dozen COVID-19-associated mucormycosis patients, two of whom underwent complete eye removal. Pre-pandemic, he would encounter two to three mucormycosis cases every year.

“It’s a serious rise,” he says. “We never expected it.” On Sunday, the Indian Council of Medical Research issued an advisory for the screening, management and diagnosis of mucormycosis in the time of COVID-19.

For now, though, these unexpected infections have brought new challenges for patients who are already physically, emotionally, and financially depleted from a recent COVID-19 infection.

The surging demand for antifungal medication has created an acute shortage, giving rise to a back market for drugs that were already too expensive for most people to afford. In an overwhelmed healthcare system, finding hospitals where mucormycosis patients can get surgery and post-operative care can be another logistical nightmare.

While India’s mucormycosis cases surface in only a small fraction of the country’s total COVID-19 case numbers, the uptick is concerning. To prevent such infections in the first place, public health experts stress that hospitals maintain hygiene, especially for equipment that dispenses oxygen. They advise that doctors prescribe steroids judiciously and suggest regular monitoring of blood sugar levels for all COVID-19 patients in the hospital and at home, even in the post-recovery period.

Editor's Note: This article originally misstated the name of an ENT surgeon at Maharashtra Medical Foundation Hospitals in Pune, India. It is Ajinkya Kelkar.

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