Mucormycosis in COVID-19 pandemic: Risk factors and linkages

Abstract

Mucormycosis is a serious and potentially fatal fungal infection caused by a type of rare but opportunistic fungal pathogen called mucormycetes. Recently, mucormycosis, also known as black fungus, made severe chaos in India during the second wave (between April and June 2021) of the tragical COVID-19 epidemic by its sudden and devastating surge with up to 50% mortality rate. While the exact cause of its sharp rise suddenly and specifically during the second wave still remains debatable, it has been noted that the people who are diabetic and have recovered from COVID-19 infection are more predisposed to mucormycosis. Nevertheless, the precise reason and mechanism(s) underlying the surge of this deadly infection needs to be investigated to comprehend its pathogenesis and pathological elements and discover rationale preventative/ therapeutic solutions. It is speculated that the indiscriminate use of steroids, antibiotics and zinc as a self-medication practice that increased during the COVID-19 epidemic may have promoted the dysbiosis of gut microbiota thereby inducing immune-suppression and making the risk group highly susceptible to this mycotic disease. In these contexts, this timely article attempts to contemplate and discuss some of the possible factors and potential mechanisms that can help to understand and explain the conundrum of sudden, steep and deadly upsurge of mucormycosis infections during the second wave of COVID-19 epidemic.

Keywords: Black fungus; COVID-19; Dysbiosis; Fungal infection; Gut microbiota; Mucormycetes; Mucormycosis; SARS-CoV-2; Steroids.

Fig. 1

(a) Trend of self-medication and usage of different types of drugs during the COVID-19 epidemic55–61. (b). Climatic conditions of the three Indian states most heavily affected by mucormycosis. (Ramakrishna et al., 2019; Choudhary et al., 2021; Sadio et al., 2021; Chopra et al., 2021; Quispe-Cañari et al., 2021; Makowska et al., 2020; Wegbon et al., 2021; Dare et al., 2021)