Root Causes of Fungal Coinfections in COVID-19 Infected Patients

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has infected over 200 million people, causing over 4 million deaths. COVID-19 infection has been shown to lead to hypoxia, immunosuppression, host iron depletion, hyperglycemia secondary to diabetes mellitus, as well as prolonged hospitalizations. These clinical manifestations provide favorable conditions for opportunistic fungal pathogens to infect hosts with COVID-19. Interventions such as treatment with corticosteroids and mechanical ventilation may further predispose COVID-19 patients to acquiring fungal coinfections. Our literature review found that fungal coinfections in COVID-19 infected patients were most commonly caused by Aspergillus, Candida species, Cryptococcus neoformans, and fungi of the Mucorales order. The distribution of these infections, particularly Mucormycosis, was found to be markedly skewed towards low- and middle-income countries. The purpose of this review is to identify possible explanations for the increase in fungal coinfections seen in COVID-19 infected patients so that physicians and healthcare providers can be conscious of factors that may predispose these patients to fungal coinfections in order to provide more favorable patient outcomes. After identifying risk factors for coinfections, measures should be taken to minimize the dosage and duration of drugs such as corticosteroids, immunosuppressants, and antibiotics.