Mucormycosis : The Black Fungus hitting COVID-19 patients

Dr Mudra Ingawale *

As the deadly second wave of COVID-19 ravages India, doctors all over the Nation are reporting cases involving a rare infection called Mucormycosis, falsely named the "black fungus". The term got associated with mucormycosis due to the presence of black dots among the culture of white fungal colonies. This fungal infection is pushing some recovered Covid patients into yet another deep crisis.

Mucormycosis is a serious but rare fungal infection caused by a group of fungi called Mucormycetes. These fungi are commonly found in soil, plants, manure and decaying fruits and vegetables. It is ubiquitous and is found in air and even in the noses of healthy people.

It mainly affects people whose immunity is suppressed eg. People with diabetes associated with ketoacidosis, patients on chemotherapy and transplant patients on immunosuppressive drugs can be affected. It can also affect the sinuses, eyes, brain and lungs.

This sudden surge in number of Mucormycosis cases can be attributed to the new mutant of the Covid virus which raises the blood sugar level in diabetics and also in non diabetics. It can also be attributed to the use of steroids, a life saving treatment for severe and critically ill COVID-19 patients. Steroids act as a double edged sword.

They reduce inflammation in the lungs for covid-19 however they also reduce the immunity and raise blood sugar levels. Diabetes lowers the body's immune defences; coronavirus further impairs the defences while steroids add fuel to the situation. It is thought that this drop in immunity could be triggering the current increases in cases of Mucormycosis.

Presentation of two types of Mucormycosis have been commonly observed with covid-19 patients, whether active, recovering or post discharge. This includes Rhino-Orbital-Cerebral Mucormycosis (ROCM) and Pulmonary Mucormycosis.

Clinical features, signs & symptoms in Mucormycosis:
A. Rhino-Orbital-Cerebral Mucormycosis :

Rhino-Orbital-Cerebral Mucormycosis in simple words the fungus affects noses, eyes and brain. This disease originates from the nose and rapidly spreads along the sinus passage to infect the orbit (bone cavity which surrounds the eye) and brain. Hence, the infection can be classified into three stages.

Initial stage, the patient will experience either nasal blockage or congestion, nasal discharge (bloody or brown/black) and localized pain inside the nose. The patient will then start to develop facial pain, numbness or even swelling of the face.

As the infection progresses and reaches the orbit, the patient begins to experience headache and orbital pain, which means pain in or behind the eye , blurred or double vision with pain, vision loss in one or both eyes, partial or complete blindness.

Toothache, loosening of teeth located in the upper jaw and dysfunction in jaw movement. Paresthesia, or abnormal sensation in the skin such as tingling, chilling or numbness can be experienced. Patients also exhibit fever, skin lesions and a black eschar on the skin near eyes or nose. Unstable gait, altered consciousness and seizure indicate the spreading of the fungus to the brain.

B. Pulmonary Mucormycosis

Primarily affecting the lungs and respiratory system, Pulmonary Mucormycosis is common among immune compromised patients whose immune systems have lowered ability to fight infections and diseases. Patient with Pulmonary Mucormycosis exhibit symptoms including fever, cough, shortness of breath and chest pain. Some individuals go through hemoptysis as well, which means coughing up blood.

Respiratory symptoms worsen as the infection spreads and patients may observe pleural effusion which means fluid collection in outer covering of lungs.

Risk Factors:

o Uncontrolled diabetes mellitus -blood sugar is high and the tissues become relatively acidic – a good environment for fungi to grow
o Immuno-suppression by steroids
o Prolonged ICU stay
o Co-morbidities- post transplant/malignancy
o Voriconazole therapy etc.

How to prevent Mucormycosis ?

o Being vigilant about the early signs and symptoms and seek medical attention at the earliest,
o Tight regulation on blood sugar levels, monitoring blood sugar levels regularly post covid -19 discharge and also in diabetics is crucial
o Use steroids judiciously-correct timing, correct dose and duration.
o Use clean, sterile water for humidifiers during oxygen therapy.
o Use masks if you are visiting dusty construction sites.
o Wear shoes, long trousers, long sleeve shirts and gloves while handling soil (gardening), moss and manure. Maintain personal hygiene including thorough scrub bath.

How to diagnose Mucormycosis :

If a patient exhibits symptoms of Mucormycosis, it must be treated as a medical emergency and clinical diagnosis must be carried out immediately. Suspected patients should undergo appropriate radio-imaging study. MRI–PNS (paranasal sinuses) with brain contrast study for RCOM. Plain CT Thorax for pulmonary mucormycosis.

Treatment of Covid associated Mucormycosis :

This disease when detected in early stage can be treated with medications and cure the patient without further complications. Control diabetes, maintain judicious use of steroids, discontinue immune-modulation drugs, proper use of anti-fungal drugs under medical supervision, nasal endoscopy are important ways to treat the disease in early stage .

In advanced cases surgical debridement may be eventually required to remove necrotic (dead) tissue. A team approach is required which include infectious disease specialist, microbiologist, neurologist, ENT specialist, ophthalmologist, neurologist, dentist, surgeons (maxilla facial /plastic) and Radiologists.

In this difficult time of current pandemic, when doctors are overburdened with COVID-19 patients, Mucormycosis has become a challenging affair.

There is no doubt that the 'Black fungus' has a cascading effect, adding to our Covid woes. Doctors and healthcare workers are fighting relentlessly and dealing with this efficiently with teamwork. The only way to get out of this with minimal all round damage is to stay vigilant.