More than 3.5 million people have died worldwide from COVID-19 infection and the numbers are only rising despite more than a year into this public health emergency, specifically in developing countries.
Although the clinical manifestations of this disease are well-established the long-term consequences are still evolving and are being studied. Infection with ‘Black’ fungus is one such complication that is increasingly seen in patients with COVID-19 infection, particularly in India and other Asian countries. ‘Black’ fungal infection, known as Mucormycosis or Zygomycosis in medical terminology, is an opportunistic infection. It is labeled as ‘black’ due to the physical appearance of dead tissue caused by this fungal infection.
As a physician, some of the common questions that I frequently encounter from my patients, family, and friends are on ‘Black’ fungus. Here, I attempt to answer the questions:
How is black fungus infection acquired?
The most common causative organisms of this illness belong to genera Rhizopus, Mucor, and Rhizomucor. They are found ubiquitously and are commonly acquired through the inhalation of spores. This is typically seen in patients with severe immunocompromised states.
Who is likely to get black fungus/Mucormycosis?
Mucormycosis is not seen in all patients diagnosed with COVID-19 infection. But some of the underlying comorbidities can make patients more susceptible to acquire this infection. Patients with uncontrolled Diabetes Mellitus, cancers (particularly blood cancers), organ transplants, and those on immunosuppressive therapy are at increased risk of getting this fungal infection.
Why is black fungus increasingly seen in COVID-19 patients?
The relationship of COVID-19 infection with Mucormycosis is still unclear. But it is known that the fungi causing this infection thrive well in high glucose and acidic environments. It is important to remember that steroids, which are commonly prescribed in the treatment of COVID-19 pneumonia, increase patient blood sugar levels and suppress one’s immunity. This can put him/her at risk of acquiring Mucormycosis.
What symptoms to watch for?
Patients at risk should watch for symptoms such as nasal discharge often with fevers, facial pain, headaches, orbital pain or swelling, decreased / loss of vision, or double vision. Blood in cough or vomitus may also be seen. The development of any of these symptoms should prompt immediate evaluation by a physician.
Is there any treatment for Mucormycosis?
The fungi causing Mucormycosis spread rapidly and invade blood vessels resulting in the death of infected tissues. Patients diagnosed with Mucormycosis typically require hospitalization and initiation of antifungal therapy as soon as possible. This illness has a risk of significant morbidity and mortality. Patients require urgent surgical debridement to remove the dead and necrotic tissues. Hence consultations with ENT and or a maxillofacial surgeon are required. Ophthalmology consultation is also required if orbits are involved.
What can be done to prevent this fungal infection?
Patients who are on chronic immunosuppressive therapy should consult physicians before initiating any new medications. Indiscriminate use of steroids, such as using steroids for patients with mild COVID-19 infection, should be avoided. Over-the-counter dispensing of steroids should be banned and strictly enforced by pharmacists. Patients who require steroids should have their blood sugars monitored and sugars need to be corrected, typically with insulin injections. In short, controlling blood sugars well mitigates the risk of Mucormycosis.
Dr. Shivaraj Nagalli is a board-certified Internal Medicine physician and a fellow of the American College of Physicians. He practices Hospital Medicine at the Shelby Baptist Medical Center in Alabaster, Alabama.