As India grapples with a deadly second wave of coronavirus, authorities have warned of a rare fungal infection that can maim or even turn fatal if left uncared for. Several media reports have said that doctors in the country are reporting cases of “mucormycosis”, informally known as “black fungus,” among recovering or recovered Covid-19 patients in states like Maharashtra and Gujarat as well as in Delhi.
Mucormycosis (previously called zygomycosis) is a serious but rare fungal infection caused by a group of molds called mucormycetes. These molds live throughout the environment. Mucormycosis mainly affects people who have health problems or take medicines that lower the body’s ability to fight germs and sickness.
It most commonly affects the sinuses or the lungs after inhaling fungal spores from the air. It can also occur on the skin after a cut, burn, or another type of skin injury. People get mucormycosis by coming in contact with the fungal spores in the environment. For example, the lung or sinus forms of the infection can occur after someone breathes in spores.
Mucormycetes, the group of fungi that cause mucormycosis, are present throughout the environment, particularly in soil and in association with decaying organic matter, such as leaves, compost piles, and animal dung. 1 They are more common in soil than in air, and in summer and fall than in winter or spring. 2-4 Most people come in contact with microscopic fungal spores every day, so it’s probably impossible to completely avoid coming in contact with mucormycetes.
These fungi aren’t harmful to most people. However, for people who have weakened immune systems, breathing in mucormycete spores can cause an infection in the lungs or sinuses which can spread to other parts of the body.
Transmission of this fungal infection occurs through inhalation, inoculation, or ingestion of spores from the environment. Although most cases are sporadic, healthcare-associated outbreaks have been linked to adhesive bandages, wooden tongue depressors, hospital linens, negative pressure rooms, water leaks, poor air filtration, non-sterile medical devices, and building construction. Community-onset outbreaks have been associated with trauma sustained during natural disasters.
A definitive diagnosis of mucormycosis typically requires histopathological evidence or positive culture from a specimen from the site of infection. Specimens from sterile body sites offer stronger evidence of invasive infection compared to colonization.
Culture of non-sterile sites (e.g., sputum) may be helpful in patients with infection that is clinically consistent with mucormycosis. Mucormycetes may be difficult to differentiate from other filamentous fungi in tissue; experienced pathological and microbiological assistance is often helpful.
No routine serologic tests for mucormycosis are currently available, and blood tests such as beta-D-glucan or Aspergillus galactomannan do not detect mucormycetes. DNA-based techniques for detection are promising but are not yet fully standardized or commercially available.
Early recognition, diagnosis, and prompt administration of appropriate anti fungal treatment are important for improving outcomes for patients with Mucormycosis. 2 Amphotericin B, posaconazole, and isavuconazole are active against most mucormycetes. Lipid formulations of amphotericin B are often used as first-line treatment. In addition, surgical debridement or resection of infected tissue is often necessary, particularly for rhinocerebral, cutaneous, and gastrointestinal infections. 2,4 Control of the underlying immunocompromising condition should be attempted when possible.
The common symptoms include nasal congestion and discharge, one-sided facial pain, numbness or swelling, toothache and loosening of teeth, blurred or double vision, redness around eyes, fever, breathing difficulties as well as chest pains.
Indian Council of Medical Research (ICMR) said patients who have had prolonged stays in intensive care units or are immunosuppressed due to steroids can also be at risk. Many severe Covid-19 patients in India are being treated with corticosteroids like dexamethasone, an anti-inflammatory drug that also reduces the immune system’s ability to fight infections and other disease to alleviate symptoms, making them more susceptible.
Dr Hetal Marfatia, professor and head of the ENT department at the government-run KEM hospital in Mumbai, said a surge in mucormycosis cases is being witnessed in the last two weeks. “On average, two or three such patients are visiting the hospital every day,” he said. Many of these patients come from outside Mumbai and cannot afford the treatment cost, he said.
During the first phase of the COVID-19 pandemic the fungal infection typically came to light a couple of weeks after patients were discharged, Dr Marfatia said. “But now, some patients are contracting this infection while undergoing COVID-19 treatment,” he added.
In the state of Maharashtra, where Mumbai is located, 200 individuals caught mucormycosis after recovering from COVID-19, and eight have died from the black fungus. Cases are also appearing in the capital city of Delhi and in the state of Gujarat, where the state government has ordered 5,000 doses of the antifungal drug amphotericin B to treat the disease.
“We have heard that in some areas, people who are COVID-infected or recovered suffer from mucormycosis, but there is not a big outbreak of it,” Dr. V.K. Paul, head of India’s Covid task force, said at a press conference last week. “We are watching and monitoring.”