Mucormycosis or Black Fungus – The new face of Covid-19 pandemic
As India continues to battle the Covid 19 pandemic, new deadly complications of the infection have surfaced. The Coronavirus now poses a greater challenge in the form of the deadly fungal infection mucormycosis or as the media has named it ‘Black Fungus”.
India is in a turmoil and the fungal infection has emerged as the newest enemy in the battle against coronavirus. Even though our state has only reported 15 to 20 number of cases, Northern parts of India have reported above 8000 cases. Hence we should be cautious and keep a watch for this devastating fungal infection.
Is mucormycosis dangerous?
With a killing rate of 70%, this infection is to be feared. Once infected, the patient needs antifungal therapy with aggressive surgeries which may include removal of eye and facial bones. The treatment takes weeks to months to complete and patients can end up with permanent loss of vision and difficulty in taking food orally leading to dependency on tubes for feeding.
Even a slight delay in the diagnosis or management can lead to devastating morbidity and mortality. However, the disease can be optimized by early diagnosis and aggressive treatment. Late presentations, shortage of antifungal drugs, shortage of hospital beds and ventilators for post-operative care are some of the burdens faced by doctors treating the infection.
What is mucormycosis?
The fungus is commonly seen around us in the soil, plants and decaying vegetables but rarely affects us. It is a rare aggressive opportunistic fungal infection, commonly seen in patients with low immunity. The mode of infection is usually inhalation and infection begins in the nose and paranasal sinuses with invasion of the vascular supply which leads to reduced blood supply and necrosis of nearby tissue and bone. The fungus can enter nearby structures like eye, brain from the paranasal sinuses leading to more complications. The fungus is very aggressive in spreading to nearby structures and only take hours to days to worsen the condition of the patient
Who are at risk?
Uncontrolled blood sugars and low immunity are 2 favourable factors for the fungus to grow. It is commonly seen in patients with immunocompromised states like uncontrolled diabetes mellitus, post solid organ transplantation, iron overload, Covid-19 infection, on high dose or long term corticosteroids or immunosuppressive drugs, malignancies etc.
Why are Covid 19 infected patients more prone to mucormycosis?
There is an increasing incidence of mucormycosis involving the eye, nose, paranasal sinuses and brain in COVID-19 patients in India currently. This is due to the low immunity caused by the Covid 19 infection and associated risk factors like existing Diabetes Mellitus, malignancies, chronic kidney diseases etc. Steroid therapy given during the treatment of Covid 19 infection further worsens the immunity.
Almost all patients that present to us give a history of recent Covid-19 infection, uncontrolled blood sugars during the Covid infection and history of steroid intake (given either too soon, or for too long or at a high dose).
Some patients who were in pre diabetic stage prior to Covid 19 infection, developed high blood sugar level post steroid intake during the Covid 19 infection which made them at risk for getting mucormycosis. Very few patients with mucormycosis who were non diabetic but had other comorbidities like kidney disease on dialysis or having blood malignancies have also presented with history of recent Covid 19 infection with high steroid use.
Covid 19 infection with steroid use is the common denominator in almost all cases we have seen so far. The immunosuppressed state caused by the Covid-19 infection and steroids taken seems to be the major triggering factor for this dangerous fungal infection. Hence patients who are infected with coronavirus and are on steroids should be closely observed for early signs of mucormycosis. In case of any suspicion, an immediate otorhinolaryngology and ophthalmology consultation should be sought.
What are the signs and symptoms?
Warning symptoms of mucormycosis are visual disturbances like double vision, restriction of eye movements or sudden loss in vision, eye swelling or pain, jaw or dental pain, unilateral facial swelling or pain, nasal block or epistaxis, severe headache, altered sensorium and fever.
How to diagnose?
Patients with suspected mucormycosis should undergo nasal endoscopy and oral examination with biopsy from a suspicious area. Otorhinolaryngology examination shows blackish discoloration over nasal turbinates, blackish foul smelling crusts or pale nasal mucosa that does not bleed on touch. Ulcer or blackish discoloration over palate or upper alveolus or loosening of teeth is seen if the maxilla is involved. The affected area is usually painless on touch. Complete ophthalmology and neurology examination should be carried out to know the extent of the disease.
Diagnosis is by microbiological tests and histopathology. Specimens taken from the nasal or oral cavity are sent for fungal KOH test, fungal culture and histopathology. Additional pus culture should be done to rule out superimposed bacterial infection.
The radiological investigation of choice is contrast MRI study of the paranasal sinuses, orbit and brain. Ischemia (loss of blood supply) and non-enhancement of involved paranasal sinuses and turbinates is seen on MRI (black turbinate sign). Mucormycosis lesions tend to be isointense or hypointense in MRI.
The treatment of mucormycosis is antifungal therapy with surgical debridement of the involved area.
Antifungal therapy includes starting the patient on Injection antifungal (Amphotericin B 5mg/kg/day) for at least 2-3 weeks. Kidney impairment can occur with antifungal therapy hence regular monitoring of renal function and dose modification is needed. Daily monitoring of electrolytes, renal function and blood sugar levels is needed in these patients who are on antifungal. Antifungal therapy is expensive and patients usually require hospital stay for weeks adding to the financial constraints of the patient.
Surgical management is aggressive as the priority is to save the life of the patient. Early endoscopic removal of diseased areas in the nasal cavity and involved paranasal sinuses and/or total or partial removal of facial bone depending on the extent of disease. Surgery is mostly disfiguring with removal of eye and/or facial bones in most patients. In case of extensive disease involving the eye with complete loss of vision- eye will have to be removed. If there is only limited eye involvement, local injection of antifungal drug into the eye with frequent imaging and eye evaluation at regular intervals is done in an effort to save the eye.
The patients usually require multiple surgeries and morbidity associated with debridement is high. Due to their recent history of Covid 19 infection and lung status, most patients require post-surgery ICU stay with ventilator support. Surgery is done to remove the diseased area and reduce fungal load to prevent further spread of disease. Post-surgery the patient is continued on antifungal therapy for weeks. Regular examination of the operated site and MRI scans at intervals are done to prevent recurrences.
Treatment of mucormycosis is emotionally, mentally and financially exhausting for the patient and family. Even after aggressively treating the infection with surgery and antifungal therapy, half the patients lose their lives and the rest may have permanent loss of vision and/or difficulty in taking food orally.
‘Prevention is better than cure’ holds more significance than ever in the current scenario. Now is the time to show caution. Limiting the use of steroids in Covid 19 infection, strict monitoring of blood sugars in patients receiving steroid therapy, vaccinating the population to reduce the severity of Covid 19 infection, creating awareness regarding the early signs and symptoms of mucormycosis, maintaining good oronasal hygiene with avoiding reuse of disposable masks, maintaining cleanliness of the hospitals, patient surroundings, nasal prongs and oxygen masks in hospitalized patients, early diagnosis with prompt treatment are some of the measures that can be followed.
India has survived many crises in the past. This too shall pass. Be aware. Be safe. We shall survive this battle too.
(The author is working as ENT surgeon in Artemis Hospitals, Gurgaon, Haryana)