Black Fungus: Another Risk with COVID-19

One of the ironies of medicine is that the treatments for one problem can set the stage for the entry of another.  This is what happens with the so-called “black fungus” that has ravaged COVID-19 patients first noticed earlier this summer in India, and now in the U.K., France, the U.S: and elsewhere, as reported in the Guardian of July 1.

Caused by the mucurmycetes molds, black fungus, like other mushrooms, grow on a forest floor carpeted with wet, rotten and decaying leaves and wood, compost, and animal dung.  And like other fungi, they release spores into the air, and thus are transmitted into the lungs.  Mucormycosis is not a contagious disease, but transmitted via inhalation or a break in the skin. But it’s also possible to ingest the spores, though that is less likely to cause disease. 

However, as with most molds, infection in a healthy person is usually fended off by the immune system, and a range of useful bacteria present in the human body.  But weakened immune systems, combined with digestive and other bacteria destroyed by antibiotics, and increased blood sugar levels in poorly controlled diabetes can make COVID patients particularly vulnerable to fungal infections. 

What happens

Black fungus damages the blood vessels and then reduces blood flow to tissues, leaving them necrotic (dying), eventually turning black.

The spores mainly lodge in the nose, sinuses and lungs. Once in the upper respiratory tract, the person might develop rhinosinusitis. It could start with a running nose, red eyes or pain and swelling of the sinuses, but later the person might develop fever, shortness of breath. From here, the spores can spread into the bone, eyes and brain, gastrointestinal tract and major organs and can also get into the circulatory system and spread throughout the body. 

The spores can also enter via the skin and cause redness, swelling, and eventually black sores. 

Either way, mucormycosis can be fatal, with an estimated death rate of over 40%, with the highest mortality in people with disseminated disease and lowest with skin infections.

Who’s at risk?

The people at most risk have a weak immune system. Usually, they’re immunosuppressed, after cancer treatments or transplants, have a low white blood cell count, are on steroid therapy or other immunosuppressant medications, or have uncontrolled diabetes. But healthy people, too, can get sick if the spores enter the body through broken skin. 

Making the diagnosis

The usual symptoms for sinusitis include nasal, a bloody or black nasal discharge, local pain on the cheekbone, numbness or swelling or pain on one side of the face. Sometimes, people have discoloration on the bridge of the nose, and they could experience problems with their jaw and teeth, eye pain with blurred or double vision, and black skin lesions. 

So if there is a suspicion, have a culture, or better, a biopsy, taken in the area involved. The diagnosis is made when the fungi are identified along with related inflammation. 

And speed is of the essence, treating with a strong intravenous antifungal medication like amphotericin B.  However, the most effective treatment is the surgical removal of the affected dying tissue, which can be disfiguring. However, a systemic or brain infection can be fatal, so it is usually worth it. 

Can I get mucormycosis in Europe?

Yes, you can. But thankfully, it’s rare, with less than 2 cases per million people, but in India, the prevalence is about 80 times higher than in developed countries. There have been CAM cases in Europe, the Middle East, North and South America. One recent report described four cases in the Netherlands. 

Tips to reduce the risk of mucormycosis

Because these common fungal spores are in the air, it’s impossible to avoid them. But there are a few things to do to avoid getting a severe infection. 

  • People with diabetes need to control their blood sugar
  • Wear an N95 respirator face mask, especially outdoors
  • People with severe COVID-19 on corticosteroids, especially intravenous corticosteroids, require careful monitoring and reducing the dose as appropriate 
  • Cautious use of antibiotics, antifungals, immunosuppressant therapies
  • Wear fresh, clean masks, and clean any instrument used over your nose or mouth like an inhaler or a positive pressure mask for sleep apnea to avoid inhaling molds deep into the lungs
  • if you’re a diabetic or immunosuppressed or had an organ transplant, avoid dusty and moldy places – construction or excavation sites, water-damaged buildings
  • Avoid close contact with soil or dust, e.g., gardening
  • If gardening, then wear protective clothing, including a face mask when in areas with dust and mold
  • Wear long clothes – long pants, a long-sleeved shirt and shoes when gardening or walking in a forest to avoid skin exposure
  • Wear gloves when handling soil, moss, or manure, compost (rotting food), fallen leaves
  • Clean areas of broken skin with soap and water
  • See your doctor if you’re worried and discuss the options for antifungal medicationor other preventive measures