Is there an association between zinc and COVID‐19–associated mucormycosis? Results of an experimental and clinical study

Abstract

Background The enormous increase in COVID‐19–associated mucormycosis (CAM) in India lacks an explanation. Zinc supplementation during COVID‐19 management is speculated as a contributor to mucormycosis. We conducted an experimental and clinical study to explore the association of zinc and mucormycosis. Methods We inoculated pure isolates of Rhizopus arrhizus obtained from subjects with CAM on dichloran rose Bengal chloramphenicol (DRBC) agar enriched with (three different concentrations) and without zinc. At 24 h, we counted the viable colonies and measured the dry weight of colonies at 24, 48 and 72 h. We also compared the clinical features and serum zinc levels in 29 CAM cases and 28 COVID‐19 subjects without mucormycosis (controls). Results We tested eight isolates of R arrhizus and noted a visible increase in growth in zinc‐enriched media. A viable count percentage showed a significantly increased growth in four of the eight isolates in zinc‐augmented DRBC agar. A time‐ and concentration‐dependent increase in the mean fungal biomass with zinc was observed in all three isolates tested. We enrolled 29 cases of CAM and 28 controls. The mean serum zinc concentration was below the reference range in all the subjects and was not significantly different between the cases and controls. Conclusions Half of the R arrhizus isolates grew better with zinc enrichment in vitro. However, our study does not conclusively support the hypothesis that zinc supplementation contributed to the pathogenesis of mucormycosis. More data, both in vitro and in vivo, may resolve the role of zinc in the pathogenesis of CAM.

Evaluation of hospital environment for presence of Mucorales during COVID-19-associated mucormycosis outbreak in India – a multi-centre study

“…1 Though poor glycemic control and inappropriate steroid therapy were found to be important risk factors for development of mucormycosis [ [2] , [3] , 4 ], myriad hypothesis like high Mucorales spores in air, contamination of oxygen supplies, respiratory equipment, humidifier water, reused face masks, zinc supplementation are proposed for the causation of COVID-19 associated mucormycosis (CAM) outbreak [ 5 ]. Recently, our study does not conclusively support the hypothesis that zinc supplementation contributed to the pathogenesis of CAM [ 6 ]. However, considering earlier reported iatrogenic transmissions of Mucorales in susceptible patients through hospital linen, contaminated catheters, arm rest, tongue depressors, and construction activities [ 7 , 8 ], we planned the present multi-centre study to evaluate possible environmental contamination by Mucorales at Indian hospitals during the outbreak period.…”

Clinical Features and Mortality of COVID-19-Associated Mucormycosis: A Systematic Review and Meta-Analysis

“…[ 27 ] India Prospective Single-center 70 Mar 2020–Dec 2020 [20–75] 67 (47) 100 (70) Patel A. [ 28 ] India Retrospective Multi-center 187 Sep 2020–Dec 2020 57 ± 13 80 (150) 60 (113) Dubey S. [ 29 ] India Retrospective Single-center 46 Apr 2021–Jun 2021 53 ± 10 64 (29) 100 (46) Bhanuprasad K. [ 30 ] India Prospective Single-center 132 Jun 2020–Jul 2021 51 ± 12 77 (101) 98 (129) Selarka L. [ 31 ] India Prospective Multi-center 47 Jan 2021–Mar 2021 55 ± 13 75 (35) 77 (36) Muthu V. [ 32 ] India Retrospective Single-center 31 – 53 [48–58] 76 (23) 75 (21) Pakdel F. [ 33 ] Iran Cross-sectional …”

Pulmonary mucormycosis in the aftermath of critical COVID-19 in an immunocompromised patient: Mind the diagnostic gap

“…Our patient had high levels of ferritin throughout the course of infection. Due to low plasma-levels of zinc, he received zinc-supplements, which has been found to improve growth of Rhizopus [9] . He had SBS, received parenteral nutrition and had corticoid-induced hyperglycemia.…”