We live in uncertain times. The second wave of the pandemic, along with the looming threat of the ‘black fungus’, has laid waste to hundreds of thousands of people. Mucormycosis, colloquially known as the black fungus, has been found to grow in the soil, damp areas, old buildings and may even live in our noses. Historically, mucormycosis has been diagnosed in patients with uncontrolled diabetes and in immunocompromised patients such as those with AIDS. We are now seeing a resurgence of the disease in the wake of the second Covid wave. Patients usually present with symptoms in the third week of illness when they seem to be on the path to recovery. Commonly, patients complain of eye pain and sinus issues, while lung and gastrointestinal involvement are not unheard of.
The pertinent question that has to be answered today is why are we seeing an explosion of mucomycosis now, during the second wave, when treatment protocols, especially the use of steroids, have not changed all that much. Off the bat, steroids, used in appropriate doses, are life-saving drugs in the treatment of Covid pneumonia, as evidenced in the RECOVERY trial. Hence, steroids in themselves cannot be the scapegoat in this fresh epidemic of black fungus. While the exact ethology of mucormycosis in Covid will require extensive study and research, a few ideas that can contribute to a better understanding of the nature of the relationship between the two are as follows
1. The new mutant strain of the coronavirus potentially has a greater suppressive effect on T cell immunity leaving the body defenceless in the face of secondary infections. Combined with the immunosuppressive action of steroids and other drugs like tocilizumab along with comorbidities including uncontrolled diabetes, it provides a fertile breeding ground for fungal spores leading to florid mucormycosis.
2. Excessive use of steam inhalation, as advised by WhatsApp gurus, has led to scalding of the nasal passages in patients, which on exposure to fungal spores can serve as a site for infection. Another aspect of steam inhalation is the unknown quality of the water being used for inhalation purpose; the use of a contaminated water source can be a potential locus for infection.
3. While use of face masks is the golden rule for preventing coronavirus spread, reusing the same mask many times without proper cleaning can be a potential cause for the rapid spread of mucormycosis in this second wave.
The population at risk of contracting mucormycosis include those with uncontrolled diabetes and severe Covid pneumonia, immunocompromised patients on long-term steroid/immunosuppressive treatment, prolonged ICU stay and renal failure. As mucormycosis can have a variety of presentations, early diagnosis is crucial for favourable clinical outcomes. Preferred modalities of investigation include nasal endoscopy, functional endoscopic sinus surgery, bronchoalveolar lavage and lung biopsy that are used to demonstrate the fungal presence in the body. Once the diagnosis has been established, treatment protocols have to be instituted aggressively. Surgical debridement, use of Amphotericin B and other antifungal agents for around three-six weeks constitute the mainstay of treatment.
Surviving Covid pneumonia is an ordeal that saps the body of its vitality, allowing the black fungus to deliver the knockout punch. Extensive media coverage about the black fungus has led to fear among the public about the use of steroids in the treatment of Covid pneumonia. It becomes important to dispel this myth, and educate the public that the use of steroids in appropriate doses can be life-saving. As healthcare workers, it is imperative that we have a detailed discussion with the patient and their family about the role of steroids in the treatment of Covid pneumonia. Another common query is whether there is any preventive medication for mucormycosis. Use of prophylactic medication is uncommon, but steps can be taken to reduce the risk. Some suggestions that can be followed are wearing a clean mask, avoiding excessive steam inhalation, Covid-appropriate behaviour and proper control of diabetes under the guidance of an endocrinologist.
Theories linking the new mutated strain of Covid pneumonia with increased immune suppression leading to mucormycosis have to be thoroughly investigated and research into novel treatment protocols have to be initiated. We have to put the lessons we have learnt from two devastating waves of the pandemic to use and get ahead of this black fungus epidemic. The mantra to navigating this successfully remains the same: wear masks, maintain social distance, observe appropriate hand hygiene and get vaccinated at your turn. Stay safe.
Dr Satyanarayana Mysore
(Renowned Pulmonologist and HOD, Sleep Medicine, Manipal Hospitals, Bengaluru)
(satya.mysore@gmail.com)