Dr. Vivek Baliga
Cardiologist and Consultant Physician
Dr. Vivek Baliga B. is a consultant physician and cardiologist, and director of Baliga Diagnostics in Bangalore. He is a keen advocate of patient education and loves to blog about all things health related. Learn more about him at drvivekbaliga.com. The article first appeared in Dr. Baliga’s website heartsense.in
Here we go again. First we had COVID, now we have Black Fungus.
Over the last few weeks, there have been numerous reports on ‘black fungus’ in patients with COVID 19 infection. It sounds quite grim. Some articles have even gone on to declare it an epidemic.
I thought I would put together a short article on what black fungus is, and how it is being managed in the hospital. I have included in this article inputs from an esteemed colleague of mine, Dr. Rohit Udaya Prasad, an ENT consultant at Aster RV hospital, JP Nagar, Bangalore.
Here are some questions that are commonly being asked about this condition.
What is Black Fungus?
Black fungus is the term being used for a condition called ‘Mucormycosis’. The most common type causing the infections currently is Rhizopus arrhizus. It is an opportunistic fungal infection, which means it attacks patients whose immune system is very weak.
The fungal spores, called mucormycetes, are seen in soil, decaying leaves and compost. The spores of the fungus are floating in the air, and enter the respiratory system causing an infection. Normally, our immune system has the capability to fight a variety of bacteria and fungi. But when the immune system is down, various fungi and bacteria use the chance to infect the host, i.e. us. They can end up causing severe illnesses that need high-dose antibacterial and antifungal agents. These diseases themselves can have dire consequences.
Is this a new illness? How did it suddenly emerge?
Mucormycosis is not a new problem. It has been described previously in patients who have an immunocompromised state such as HIV infections, diabetes mellitus, and cancer. It has also been seen in patients post-cardiac transplant. Black fungus has gained notoriety in the COVID times due to the use of broad-spectrum antibiotics and high dose steroids that are used to counter the Sars CoV-2 virus.
How does black fungus affect the body?
When the fungus enters the body, the body’s defence mechanism i.e. neutrophils, line up like soldiers to fight the fungus. In those who have low immunity, the soldiers are fewer in number and a lot weaker. They are unable to fight the fungus, and this allows it to proliferate and begin to affect the body.
The Mucormycetes have the ability to survive in an acidic medium. The spores gradually grow tiny prickly tips called hyphae, and these go on and attack the blood vessels. This leads to the blood vessel getting blocked. As a consequence, the tissue that depends on the blood supply from this blood vessel becomes necrosed and dies. The area becomes black in colour (dead tissue is black, like gangrene seen in diabetes), hence the name black fungus.
Why are patients with covid illness getting black fungus infections?
Patients with COVID infection require high-dose steroids and antibiotics as life-saving treatments. A decision to start steroids for patients is a carefully thought one most times, and often medical teams have no choice but to start steroids to save a patient’s life.
Patients with diabetes tend to have a more severe COVID illness. The co-existence of diabetes makes it more likely to pick up black fungus. The high blood sugars in those with uncontrolled diabetes is a tasty food for the fungus, allowing them to grow at alarming rates.
Dr Rohit Prasad
“Patients who develop complicated diabetes, particularly diabetic ketoacidosis have higher iron levels in the blood, which is conducive for Mucormycosis to set in”, says Dr Rohit Prasad.
In those who have diabetes, steroid use is associated with erratic sugar control. Sugar levels can increase manifold. This can worsen the chance of contracting mucormycosis. Basically, the patient and the healthcare team are stuck between a rock and a hard place. Steroids will save the patient’s life, but they might give them black fungus too. It’s not an easy discussion to have with patients or their families.
In a hospital setting, black fungal spores can be present in the equipment being used such as medical devices, nasogastric feeding tubes and catheters. While these are all sterile equipment, they create a portal for entry into the body.
Rented oxygen cylinders can be a potential source as well. Given the rapid turnover, dealers may not sterilize the equipment well before renting it to another patient. Furthermore, the rust on the surface of the cylinders may carry spores. Humidified oxygen may be a source as well.
Is it a serious problem?
Mucormycosis can affect the sinuses of the face, brain, lungs, gastrointestinal tract and skin. It may even enter the bloodstream and disseminate throughout the body. The common form seen in COVID is the rhinocerebral mucormycosis i.e. the one that affects the sinuses and the brain. In patients with poor immunity, the mortality of the condition can range from 25% up to 87% in severe cases.
If the immune system’s power can be restored, then patients may have a better prognosis. However, many of them end up with surgery.
What are the signs and symptoms?
Symptoms range from a simple stuffy nose to numbness of the face, blurred vision, headache at the front of the head, fever, double vision and a runny nose.
Swelling of one side of the face has been noted as well. If you look into your oral cavity, you may see black lesions. These may also be seen on the nasal bridge. When the nasal cavity is examined, an ENT surgeon can see ulcers and areas of black necrotic areas.
If it affects the lungs, patients may develop fever, start coughing blood and become breathless. In the skin, it is seen in areas of trauma to the skin and in skin burns. There is an area of redness that swells up and eventually becomes dark and necrosed.
I will limit my discussion to these for now, as a discussion on other types is out of the scope of this article.
However, do note that black fungus can spread through the blood to various parts of the body, leading to what is called disseminated mucormycosis. This is a serious condition that can lead to a coma and even death.
How is black fungus being diagnosed in hospital?
Most patients in hospital are developing black fungus infection in the nasal sinuses. These are the air pockets that are present in the skull. A routine blood test may not really add any value. Imaging studies seem to have a better pickup rate and allow for a clear-cut diagnosis.
According to Dr. Rohit Prasad, the best way to diagnose black fungus in the sinuses is through a diagnostic nasal endoscopy. This is a procedure where a small tube with a camera at its end is inserted into the nostrils.
A CT scan of the sinuses can also help visualize the extent of the problem. An MRI scan using contrast may also be performed. A histopathology diagnosis of the tissues (an analysis of the tissue under the microscope) may be conducted through a biopsy.
Are there medicines available to treat the condition?
Fortunately, there are treatment options, but with the current pandemic availability of medicines has been a problem. This is not surprising, as Mucormycosis has never been that common a condition warranting this amount of drug manufacturing requirements.
Medical treatment will be started first in the form of antifungal agents that I have mentioned earlier. However, just medicines are NOT enough in managing this condition. This is because the blood vessels are blocked by the fungal infection. When antifungal drugs are given to the patient, they are unable to reach the affected areas through the bloodstream as these blood vessels are blocked.
If surgery is not performed, the treatment is incomplete. If you are asked to undergo surgery, do not delay it by over-contemplating the need for it. Remember, it can rapidly spread through the tissues and bones.
Protection at home
Over the last year or so, there have been numerous measures taken to ‘sanitise’ our homes, hands and possibly even our hearts. Our homes are a big source of fungal spores. I have mentioned earlier, black fungus spores are seen on rotten wood, decaying leaves, compost and soil. But they may also be present in some of the waste we have at home that accumulates during the day.
Food waste can be a potential source, so keep your waste covered. Dispose the waste every day.
Wet walls, mold formation on the walls and fungal spores within air conditioning ducts are also other sources. Make sure you get those treated by a professional.
Wearing a mask, or even double masking can be very helpful. However, don’t keep reusing the same mask all the time. Dispose them soon (if they are disposable) or wash them as often as possible.
Home oxygen concentrators and humidifiers are an overlooked source of infectious agents. If you are using an oxygen concentrator at home, make sure you use distilled water instead of tap water.
Also, ensure you get the equipment cleaned from time to time by a professional to prevent the overgrowth of bacteria and viruses in the pipes within.
Stay Home, Stay Safe
My thanks to Dr Rohit Prasad, MBBS MS, ENT consultant, Aster RV Hospital for his valuable inputs in this article.