COVID-19-associated mucormycosis in India: Why such an outbreak?

An unprecedented mucormycosis outbreak occurred in India during the second COVID-19 wave in spring 2021. COVID-19-associated mucormycosis (CAM) was observed, mainly rhino-orbito-cerebral mucormycosis (ROCM), in patients with poorly controlled diabetes and treated with inappropriate doses of glucocorticoids. The aim of this mini-review was to compare the characteristics of the CAM epidemic in India with (i) mucormycosis cases before the COVID-19 pandemic and (ii) CAM in the rest of the world (particularly in France) in order to identify the reasons for this outbreak. In India, the major mucormycosis epidemiologic change during the COVID-19 pandemic was an increase in the percentage of patients treated with corticosteroids who developed CAM. Compared with the rest of the world, India reported a higher mucormycosis incidence even before the COVID-19 pandemic. Moreover, in India, patients with CAM were more likely to have diabetes mellitus and ROCM; conversely, mortality rates were lower. The reasons for such a localized epidemic in India have remained unclear, but some hypotheses can be put forward, particularly the combination of high prevalence of uncontrolled diabetes mellitus and frequent indiscriminate corticosteroid utilization in a country that already had a high mucormycosis burden before the COVID-19 pandemic.