ABSTRACT
Since the World Health Organization (WHO) declared the pandemic of coronavirus disease-2019 (COVID-19) on March 11th, 2020, the world has faced a health crisis that includes challenges such as its diagnosis, treatment and prevention, resulting in more than 595 million confirmed cases worldwide and more than 6.4 million deaths (August 25th, 2022). The infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leads to the suppression of the immune system, particularly due to the storm of inflammatory cytokines (e.g., TNF-α, IFN-γ, IL-6, IL-2 and IL-1) and the reduction of anti-inflammatory cells (e.g., CD4+ and CD8+ T lymphocytes). These factors, when associated with the use of steroids, prolonged stay in the intensive care unit (ICU), older age, diabetes, cardiovascular and pulmonary diseases as well as inherited and acquired immunodeficiency, contribute to the colonization of other infectious agents, such as respiratory viruses, gram-positive and gram-negative bacteria, yeasts and filamentous fungi. The incidence of opportunistic fungal infections has increased significantly in patients with COVID-19, especially in individuals with critical medical conditions and presenting comorbidities, such as the ones cited above. The main fungal agents causing coinfections in these particular patients are Aspergillus spp., Candida spp. and fungi belonging to the order Mucorales. The similarity of clinical symptoms between COVID-19 and fungal infections, such as fever, dry cough, dyspnea, myalgia and headache, makes it harder to get a conclusive laboratory identification and diagnosis, which represents a challenge for treatment. To worsen this bad scenario, the available antifungals are substantially limited and some fungal species are intrinsically resistant to classical chemotherapeutic drugs used in the clinical settings. In parallel, the antifungals can also present drug interactions besides serious and severe side effects, such as hepatotoxicity and nephrotoxicity, which can greatly aggravate the patients' clinical condition. All these facts highlight the urgent need for early diagnosis of the fungal pathogens for the proper choice of antifungal treatment in order to combat these relevant yet still neglected diseases on a global scale. The present chapter focused on summarizing the main fungal infections reported in COVID-19-positive patients. © 2023 Nova Science Publishers, Inc.