Mucormycosis

What is Mucormycosis?

Mucormycosis is a lethal fungal infection caused by a large group (order) of pathogenic moulds known as Mucorales.¹

Pathogenesis

Mucorales commonly affect the lungs and sinuses, and can spread to the eye, central nervous system and gastrointestinal tract. Fungal invasion can also occur through skin breaks, and after burns or other traumatic injuries.¹

Epidemiology

Mucorales fungi are globally distributed and the incidence of mucormycosis is on the rise.^1,2 The epidemiology of mucormycosis is evolving, as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and modern diagnostic tools lead to the identification of previously uncommon genera/species, such as Apophysomyces and Saksenaea.²

The annual global incidence of mucormycosis is estimated to be greater than 10,000 cases and prognosis is poor, with an overall mortality rate ranging from 40 to 80%.^3,4 The COVID-19 pandemic led to a rise in the incidence of mucormycosis in certain geographic regions and several hundred cases of mucormycosis have been described in patients with COVID-19 (COVID-19-associated mucormycosis).^5,6 India was particularly badly affected, with over 47,000 cases of mucormycosis reported in the country between May and July 2021.⁶

Risk factors

Mucorales fungi tend to infect patients with diabetes, those who are immunocompromised and those with trauma to the skin and soft tissue.¹

Additional risk factors for mucormycosis include:^2,7,8

• Uncontrolled diabetes
• Neutropenia
• Corticosteroid use
• Major or minor trauma
• Ketoacidosis
• Solid organ transplantation
• Severe burns
• Chemotherapy
• Haematological malignancies
• Stem cell transplantation

Pathogenic species

Rhizopus spp. is the most common species (48% of cases) of Mucorales, followed by Mucor (14% of cases).⁷ Other pathogenic genera include Lichtheimia and Rhizomucor.⁷