Mucormycosis, or the grimmer popular name, “black fungus”, has evoked public concern in the context of the COVID-19 pandemic but the disease isn’t that uncommon, medical literature from India shows.
A study from 2013-2015 at four major tertiary care hospitals in India reported 388 mucormycosis cases, nearly 56% of whom were reported as having “uncontrolled diabetes”. The next biggest risk factor was “trauma”, and reported in only 10% of the cases, which underlines the critical link of the disease to diabetes. The analysis, undertaken by medics at Post Graduate Institute of Medical Education and Research, Chandigarh also found a greater proportion of the fungal infection in north India along with higher mortality, says the study that appeared in June 2019 edition of Medical Mycology , an Oxford University Press journal.
India has among the highest global prevalence of diabetes with about 9% of India’s adult population estimated to be diabetic according to the World Health Organization.
Mucormycosis is a fungal infection by a class of fungi that belong to the larger family called Mucorales. They are largely found in the soil and abundant in decaying organic material such as fruit and vegetables.
The member of this family which most often causes infection in humans is called Rhizopus oryzae. In India though, another family member called Apophysomyces, found in tropical and subtropical climates, is also common. In the study cited earlier, Rhizopus arrhizus was the most common fungus identified, followed by Rhizopus microsporus, Apophysomyces variabilis and Rhizopus homothallicus.
Those afflicted with moderate or severe COVID-19 are often administered steroids that work to dampen the immune system and prevent it from unleashing a heightened inflammatory response, called a cytokine storm that often makes COVID-19 fatal. However, in the process, the steroids tend to increase glucose levels in cells, and the curtailed immune system makes the body vulnerable to the so-called “opportunistic” infections from bacteria and fungi.
A review in the Indian Journal of Medical Research on the undetected burden of fungal infection that appeared in March this year cites a study that attempts to compute the probable extent of mucormycosis. “The burden of mucormycosis is grossly under reported, because cultures are so often negative and only recently has the first PCR (polymerase chain reaction) assay been commercialised. Incidence and prevalence of this disease is difficult to estimate because of various factors including lack of awareness of the disease even among trained physicians and lack of standardized diagnostic strategies,” the review authored by Sayantan Banerjee, David W. Denning and Arunaloke Chakrabarti notes.
They cite a study that computes India’s overall mucormycosis prevalence to be 0.14 cases per 1,000 population in India, or about 187,460 patients. The overall mortality in mucormycosis when well-treated ranges from 30% to 46.7%. This could translate to about 105,000 people succumbing to these infections every year in the WHO South East Asian Region (SEAR), were these numbers to be applied to the region.
Amphotericin B is the main antifungal drug used in treatment, though stocks ran low on the back of increased demand. Mansukh Mandaviya, Minister of State for Chemicals and Fertilizers, said five new pharma companies had been approved to produce Amphotericin-B. Before that, only six firms were manufacturing the drug.
