Brehm TT, Heyer A, Woo MS, Fischer M, von der Meirschen M, Wichmann D, Jarczak D, Roedl K, Schmiedel S, Addo MM, Lütgehetmann M, Christner M, Huber S, Lohse AW, Kluge S, Schulzer Zur Wiesch J.

Background: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, the roll-out of vaccines and therapeutic agents, as well as the emergence of novel SARS-CoV-2 variants, have shown significant effects on disease severity. Methods: Patients hospitalized at our center between January 2020 and April 2022 were attributed to subgroups depending on which SARS-CoV-2 variant was predominantly circulating in Germany: (i) Wild-type: January 1, 2020, to March 7, 2021, (ii) Alpha variant: August 3, 2021, to June 27, 2021, (iii) Delta variant: June 28, 2021, to December 26, 2021, and (iv) Omicron variant: December 27, 2021, to April 30, 2022. Results: Between January 2020 and April 2022, 1500 patients with SARS-CoV-2 infections were admitted to the University Medical Center Hamburg-Eppendorf. The rate of patients who were admitted to the intensive care unit (ICU) decreased from 31.2% (n = 223) in the wild-type group, 28.5% (n = 72) in the Alpha variant group, 18.8% (n = 67) in the Delta variant group, and 13.4% (n = 135) in the Omicron variant group. Also, in-hospital mortality decreased from 20.6% (n = 111) in the wild-type group, 17.5% (n = 30) in the Alpha variant group, 16.8% (n = 33) in the Delta variant group, and 6.6% (n = 39) in the Omicron variant group. The median duration of hospitalization was similar in all subgroups and ranged between 11 and 15 days throughout the pandemic. Conclusions: In-hospital mortality and rate of ICU admission among hospitalized COVID-19 patients steadily decreased throughout the pandemic. However, the practically unchanged duration of hospitalization demonstrates the persistent burden of COVID-19 on the healthcare system.

J Infect Public Health. 2023 Nov;16(11):1806-1812

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