India has the highest burden of mucor in the world with 140 cases per million population and, hence, the country expects to see a tidal wave of infections in the coming months.
The country, also home to the largest number of diabetic patients, second only to China, has to face the challenge of battling the invasive fungal infection, says professor and Head of Department of Neurology, Guntur Medical College, and Government General Hospital, Guntur, N.V. Sundarachary.
According to medical studies, 38% of the symptoms have occurred during the treatment of COVID-19 and 62% in the post-treatment period.
“A study of pathophysiology for invasive fungus in COVID-19 reveals that immune dysregulation after COVID-19 predisposes to secondary infection. The hyperglycemic state in COVID-19 induces damage to pancreatic cells, resulting in acute diabetes due to high expression of ACE 2 receptors in pancreatic islets. Steroids and immunosuppressants used in the COVID-19 treatment also make it predisposed to invasive fungus,” said Dr. Sundarachary.
“Black fungus is eukaryotic and has no flagella, and spreads through spores. While headache is the most common symptom, vision loss due to involvement of optic nerve cannot be ruled out. The infection can cause basal meningitis, cranial neuropathy after intracranial extension. The lesser the size, the more it causes meningitis. Fungal infections are subacute to chronic and indolent unlike bacterial infections, which are acute. All fungi are not ubiquitous as bacteria,” he said.
But the good news is that most fungi are not harmful to humans, but most fungi cause infections in immunocompromised individuals. Mucormycosis is a fungal infection involving rhino, sinus, orbital and cerebral tissues.
It is is commonly seen in patients in India, and mostly in immunosuppressed patients undergoing cancer treatment.
“The reasons are irrational usage of steroids, uncontrolled diabetes, lymphopenia in COVID-19 and contamination through oxygen humidifiers. While pulmonary mucormycosis is uncommon in COVID-19 patients, aspergillosis is a common commensal,” he said.
“Black crusts in nasal cavity, discharge from nasal cavity, swelling and numbness of paranasal sinus areas are the initial symptoms. If it spreads to orbit, proptosis, swelling and redness of orbit and eyelids, visual impairment and ophthalmoplegia are the symptoms,” said Dr. Sundarachary.
The neurological symptoms include headache, facial pain, swelling and numbness, double vision, cavernous sinus thrombosis, vision loss, focal cerebral lesions mostly stroke, facial palsy, seizures and altered mental status.
Diagnosis is through clinical, radiological features, and confirmation is through staining with KOH and, or histopathological examination.
Since it is a medical emergency, early treatment improves survival. However, early surgical excision of necrotic lesions, and antifungal therapy can reduce the risk, he said.
“The key message for prevention is use steroids in the treatment of COVID-19 in the right patient at the right time in the right dose for the right duration, and monitor and manage hyperglycemia efficiently,” Dr. Sundarachary said.