An Observational Study of Fungal Infections in COVID-19: Highlighting the Role of Mucormycosis in Tertiary Healthcare Settings

Abstract

Background Fungal infections, especially mucormycosis, have remarkably surged during the coronavirus disease 2019 (COVID-19) era, especially during the second wave peak of the pandemic raising the concern of the clinicians for the admitted patients. Steroid therapy, diabetes, and other immunocompromised states are more commonly associated with COVID-19-associated mucormycosis (CAM). Aim and objective The aim of this study is to ascertain the prevalence of fungal infections amidst the second wave of the COVID-19 pandemic and discern the associated risk factors. Materials and methods During the second peak of COVID-19, samples were received in the microbiology laboratory from all clinically suspected mucormycosis patients. These samples underwent processing for potassium hydroxide (KOH) wet mount, fungal culture on Sabouraud's dextrose agar (SDA) medium, and COVID-19 reverse transcription-polymerase chain reaction (RT-PCR) testing. All relevant clinical and associated risk factors were tabulated and analyzed. Results Among the 107 suspected cases of mucormycosis, 39 (36.4%) were confirmed positive for COVID-19 via RT-PCR, while 68 (63.6%) tested negative. Males exhibited a predominant infection rate, with the rhinocerebral system being the most commonly affected site. Significantly higher mortality rates were observed in COVID-19-associated mucormycosis (CAM) patients (33.4%) compared to those without COVID-19 (5.9%), with a notable p-value of 0.0005. CAM patients also demonstrated a higher frequency of ICU admissions (77%) compared to non-COVID-19-associated mucormycosis patients (21.4%), a statistically significant finding (p-value of 0.007). Additionally, immunocompromised states, diabetes, and the administration of oxygen therapy were identified as significant risk factors in CAM (p < 0.05). Notably, mucormycosis accounted for the majority of fungal isolates (48.27%) among COVID-19 patients. Conclusion Mucormycosis infection is more commonly seen in COVID-19-infected patients as compared to non-COVID-19 patients, especially with comorbidities such as diabetes mellitus, steroid usage, and other immunocompromised states.

Keywords: covid-19-associated mucormycosis; diabetes; fungal infection; medical comorbidities; rhizopus.

Figure 1. Broad aseptate fungal hyphae in KOH wet mount of nasal crust specimen

KOH: potassium hydroxide

Figure 2. Rhizoids, sporangiophore, and columella of Rhizopus species in LPCB mount

LPCB: lactophenol cotton blue