key: cord-0989053-b6pkue9i authors: Arakeri, Gururaj; Rao, Vishal; Amaral Mendes, Rui; Oeppen, Rachel S; Brennan, Peter A title: COVID-associated mucormycosis (CAM): is the Delta variant a cause? date: 2021-09-16 journal: Br J Oral Maxillofac Surg DOI: 10.1016/j.bjoms.2021.08.009 sha: ea46256f3d3c53ed40bb2d77cbaee1a6b0046e15 doc_id: 989053 cord_uid: b6pkue9i nan However, our study underlined that the vast majority of mucormycosis cases are that of unvaccinated people and it is possible that the vaccination has prevented or decreased the severity of adverse effects causing immune dysregulation and mucormycosis. Further, there is a possibility that the Delta virus adversely affects the pancreas, 3 thereby contributing to intense hyperglycaemia and in creating a favourable environment for the mucormycosis onset. As much as hyperglycaemia and steroid usage need to be considered as triggering factors, one must, indeed, consider that these two variables were already present even in the first wave, although no similar outbreak of mucormycosis occurred at that time. In fact, in India, the routine use of high-dose glucocorticoids for cancer patients has never resulted in a mucormycosis epidemic. Furthermore, our study also involved home isolated COVID-19 patients who only took multivitamins and were not administered steroid or oxygen. Although industrial oxygen may also be regarded as a contributing factor, its causality has not been conclusively demonstrated. Actually, it is not known why only some COVID-19 patients were infected and why cases were reported even after cessation of its use. Besides, there are many patients with CAM for whom external oxygen has never been necessary for treatment of COVID-19. Remarkably, the mucormycosis epidemic in India was followed by oxygen crisis, and many patients suffered with protracted subtle hypoxia throughout recovery, and many patients with minor symptoms were treated solely by home isolation without any oxygen. Hypoxia stimulates the endocytosis mechanism in some mucorales species, enabling the fungus metabolism to shift from carbohydrates to fatty acids, supplying fungi with extracellular lipids during infection. 4 It is possible that the combination of severe hyperglycaemia and prolonged hypoxia may have created the perfect conditions leading to a fast increase in the incidence of mucormycosis. Finally, the fact that other regions of the world with Delta virus do not have mucormycosis outbreak may be related to environmental, geographic, and genetic factors (indicated by high pre-pandemic frequency in India) that may have predisposed immunologically dysregulated individuals to mucormycosis. However, there have been cases reported in Brazil, Chile, Honduras, Mexico, Paraguay, the United States, Uruguay, Italy, and the United Kingdom. 5 In fact, the Pan American Health Organization/World Health Organization (PAHO/WHO) has advised Member States in the United States to strengthen health services to prevent CAMrelated morbidity and mortality. 5 Overall, CAM appears to be a multifaceted issue which might have resulted in immunological dysregulation and predispose individuals to mucormycosis. Until more definite data is available, prudent administration of steroids, avoidance of long-term hypoxia, and management of blood glucose levels remain key preventive factors. COVID-associated mucormycosis (CAM) in India is a multidimensional problem COVID-19 Associated Mucormycosis (CAM) in India: A formidable challenge Experts See Link Between B.1.617.2 and Black Fungus, Want Blood Sugar Monitored Like Oxygen. The wire Mucormycosis in COVID-19 2nd wave: hypoxia as key trigger and the biological impact of health policies Pan American Health Organization / World Health Organization. Epidemiological Alert: COVID-19 associated Mucormycosis