Invasive Mucormycosis (Zygomycosis) -Pre-COVID Era and COVID Era: A Comparative Retrospective Study at a Tertiary Care Centre, Chennai

Background: India has a high burden of mucormycosis among patients with uncontrolled diabetes mellitus.The estimated prevalence of mucormycosis is estimated to be 0.02 to 9.5 cases/ 100,000 persons [1].There was a localized epidemic of mucormycosis during the second wave which could be due to indiscriminate use of steroids and lapses in the infection control practices both in the hospital and at home.Treatment of this infection is challenging since it is highly invasive and intrinsically resistant to some of the antifungal agents.This study was done to compare the prevalence and clinical presentation of mucormycosis in the pre-covid era and covid era and also to compare the AFST pattern of mucormycosis during both eras.Methods: This is a single-center, retrospective study that included patients admitted during the Pre-Covid era and Covid era at a tertiary care center, in Chennai.Samples were cultured and Antifungal susceptibility testing (AFST) was performed for culture-positive isolates with amphotericin B, itraconazole, posaconazole, voriconazole, and isavuconazole by micro broth dilution method according to CLSI M38-A2.Results: Among the 365 samples received at the laboratory during the pre-covid era 52 were proven cases of mucormycosis.During the covid era, out of a total of 886 samples received, 174 were proven cases of mucormycosis.The incidence of mucormycosis was high during the COVID-19 era.Most of the risk factors and clinical presentations were similar during the pre-covid era and covid era.Still, the clinical complications were more common during the latter era.The high mean MIC values of amphotericin B drug during the pre-covid era when compared to the covid era and the higher mean MIC value of posaconazole during the covid era when compared to the pre-covid era may be due to the increased usage of these antifungals.Newer azole like isavuconazole can be considered as a good therapeutic option for the future management of resistant infections since its MIC values were found to be low.Conclusion: Timely management of the patients with the diagnosis of mucormycosis at a shorter period and administration with the right choice of antifungal agent by performing AFST will help in improved outcomes and combat the development of resistance.