Mucormycosis – an opportunistic infection in the aged immunocompromised individual: A reason for concern in COVID-19

Chavda, Vivek P; Apostolopoulos, Vasso

In the case of hospitalized COVID-19 patients, especially aging people and those with severe symptoms who require a ventilator, corticosteroids are given in an attempt to alleviate some of the symptoms. However, steroids are known to lower immunity and raise blood sugar levels, and they tend to increase clotting factors and fibrinogen concentrations in patients. This situation provides an opportunity for pathogens to evade the human immune system and infect the host. According to a recent study, the number of cases of mucormycosis (also known as zygomycosis, black fungus) have increased in COVID-19 patients who are either hospitalized or have recovered [1]. Mucormycosis affects the nose, eyes, and brain [2] and is a potentially fatal intrusive fungal infection that frequently affects immunodeficient individuals. People with type-2 diabetes with blood sugar levels higher than 220 mg/dL, autoimmune disorders, iatrogenic immunosuppression, or hematological cancers, and organ transplant recipients are especially vulnerable to mucormycosis [3]. Mucormycosis invades sinus tissues within 3 to 4 weeks [4], and rhinocerebral mucormycosis can manifest with unusual signs and symptoms comparable to severe sinusitis, such as nasal blockage, crusting, proptosis, facial oedema, ptosis, chemosis, ophthalmoplegia, in addition to headache, fever, and other neurological symptoms [5]. Black eschar is common in the nasal cavity or over the hard palate region and penetration of blood vessels, vasculitis with thrombosis, tissue infarction, haemorrhage, and acute neutrophilic infiltrates are histopathological characteristics [6]. Without early identification and treatment, the condition may proceed rapidly, with reported fatality rates from intra-orbital and cerebral complications of 50–80%. Even with quick diagnosis, treatment of underlying conditions, and vigorous medical and surgical interventions, therapy is frequently non-effective, resulting in spread and eventual death [7]. There are several hypotheses as to what else may contribute to mucormycosis infections. Some are unlikely, such as the use of industrial oxygen or ventilation systems, age-related immune complications and non-sterile water, whilst others believe that steam inhalation may play a role by impacting the mucosa, in addition to zinc supplementation being a fungal growth promoter [8].