Information about other IFD associated with COVID-19 is currently limited, likely associated with not only the lesser occurrence of these infections prepandemic, similarity in symptoms between the respiratory infections but also the difficulty in diagnosing them on a global scale, outside specialist referral centres. Infections associated with fungi endemic to certain geographical areas of the world have occurred, diagnosed using a range of tests including culture, microscopy, serologic antibody tests, antigen tests, and PCR. Few cases of cryptococcosis in the COVID-19 patient are documented but should be considered part of the differential diagnosis in high-risk patients (e.g. HIV infected), where testing cerebral–spinal fluid or serum for the presence of cryptococcal antigen by lateral flow assay is simple to perform and provides excellent performance (Se/Sp >90%) in the non-COVID-19 population.[61–63] Other forms of IFD (e.g. Rhodotorula fungaemia, Fusarium and Trichosporon infections), continue to be diagnosed in the COVID-19 patient, with diagnosis generally reliant on classical mycology.[10,15,16] Pan-fungal PCR or PCR specific to these species may play a role in the diagnosis. The detection of serum BDG may prove useful, provided BDG is present in the fungal cell wall of the specific species, while accepting that aetiological differentiation will not be feasible, which may have therapeutic consequences because of the ranging antifungal susceptibility profiles of rare yeast infections, hyalohyphomycoses and phaeohyphomycoses. Secondary infection by fungi endemic to certain geographical areas (e.g. Histoplasma, Coccidioides, Blastomyces) should also be considered in COVID-19 patients inhabiting or having recently traveled from such regions.
Curr Opin Infect Dis. 2021;34(6):573-580. © 2021 Lippincott Williams & Wilkins