Mucormycosis: A Surge in Mucorales Fungal Infection in Post – Covid Patients in Indian States and Insight into Known and Unknown Factors

Abstract

Mucormycosis is a rare opportunistic fungal infection in human caused by fungi belonging to the fungal order Mucorales and the family Mucoraceae which are now classified in the (new) phylum Glomeromycota (earlier Zygomycota), class Glomeromycetes (earlier Zygomycetes), subphylum Mucoromycotina, order Mucorales. The Mucorales comprise 55 genera with 261 species. Out of these, 39 species belonging to 12 genera viz. Actinomucor, Apophysomyces, Cokeromyces, Cunninghamella, Lichtheimia, Mycotypha, Mucor, Rhizomucor, Rhizopus, Saksenaea, Syncephalastrum, and Thamnostylum have been reported to be involved in human infections of mucormycosis. However, their prevalence niches in the states or countries is not yet well studied and documented. Clinical presentations of mucormycosis primarly include rhinocerebral, pulmonary, and cutaneous (superficial) and less frequently, gastrointestinal, disseminated, and miscellaneous forms. Pathophysiology involves inhalation of spores through the nose or mouth or even through a skin laceration. The fungus may then spread to the paranasal sinuses and consequently to the orbit, meninges, and brain by direct extension. The unchecked infection results in surgical debridement and even can be fatal. Individuals with compromised cellular and humoral defense mechanisms, diabetic patients, patients on steroid medication, and persons who had major surgeries are prone to mucormycosis infection. A surge in the cases of mucormycosis in post covid patients in the second wave of covid infection were observed in India where the mucormycosis cases increased upto 150 % in 3 weeks (May 25th to June 20th 2021) with 6.7 % of deaths.The number of cases with mortality % varied in different states of the country. The percentage of surgical debridement of eye due to mucormucosis in Nagpur district of Maharashtra state is reported for 78% patients. Even a six month old child’s death is reported due to mucormycosis in Ahmadnagar district of the state indicating the gravity of the disease. However, these mucormycosis infection is generalized as infection due to black fungus, white fungus, yellow fungus, or green fungus without naming the etiological species responsible in different parts of the country. To control this mucormycosis infection, the antifungal drug Amphotericin B is used. However, the development of resistance to this drug is already reported in some of the species causing mucormycosis. Furthermore, different species of mucormycosis fungus is reported to vary in their sensitivity to this drug. Moreover, the Amphotericin B deoxycholate is also reported to cause nephrotoxicity in some of the patients. The mucorales species are characterized by high level resistance to some of the currently available antifungal drugs. Antifungal specificity within the group may be species specific, therefore knowledge of species prevailed in the particularly area of the country is atmost important in the management strategies of the mucormycosis. Amphotericin B, Posaconazole and Isavuconazole are currently the most active drug against mucorales, however, their activity remains sub-optimal and new therapeutic strategies are needed Various known and unknown factors supportive for mucormycosis are summerised in this paper with an emphasis to have a better understanding on these for the prevention of the infections. Handling of issues like monitoring of air quality data for mucorales in metro cities and in hospitals and their displays at fortnight intervals will be worth to forecast the mucormycosis infections and management of etiological agent. Such forecast will prove a milestone for immunocompromised patients to avoid such places and thereby mucormycosis infection. The governments should make a policy for municipal corporations and hospitals to monitor and display the air quality data for mucormycosis fungi. WHO also should look and consider such important policy issues of monitoring air quality data for mucorales to deal with the emerging trends of Mucormycosis.