Mycological profile of fungi associated with rhino-orbital mycosis in post-COVID-19 patients

Abstract

Rhino-orbital mycosis is devastating fungal infection with high mortality and morbidity despite of recent advances in its diagnosis and treatment. It is caused by filamentous fungi of Mucorales order of the class of Zygomycetes. Rising number of cases presenting with fungal rhino-sinusitis with or without orbital involvement in patients recovered from coronavirus disease 2019 (COVID-19) infection was observed. Hence, present study was undertaken at a tertiary care hospital to know the mycological profile of fungi associated with these infections. Various clinical samples like deep nasal swabs, tissue from nasal cavity, nasal sinuses and orbital cavity were processed to isolate and identify fungi from suspected mucormycosis patients with standard mycological processes. Total 480 specimens from 226 patients suspected of mucormycosis were received in microbiology department of a tertiary care hospital, over 3 months period from April to June 2021. Rhino-orbital mycosis predominantly affected males and population over 50 years of age. Overall KOH positivity rate was 22.2% and culture positivity rate was 27.7% which was highest for tissue samples followed by deep nasal swabs. Most common isolate was Rhizopus spp. (51%) followed by Mucor (22%), Aspergillus (13%) and Rhizomucor (5%). Mixed infections with Mucor and Aspergillus were seen in 4% patients. Mucormycosis was observed in majority of post-COVID-19 patients and patients with high blood sugar. The majority of patients (64.1%) were suspected to have nasal involvement. Early diagnosis and prompt treatment play pivotal role in cases of mucormycosis. One should be vigilant to diagnose rhino-orbital mycosis as it is dreaded complication.