Comparison of Patients Infected With Delta Versus Omicron COVID-19 Variants Presenting to Paris Emergency Departments
Authors: Donia Bouzid, Benoit Visseaux, Christian Kassasseya, Asma Daoud, Florent Fémy, Christelle Hermand, Jennifer Truchot, Sebastien Beaune, Nicolas Javaud, Olivier Peyrony, Anthony Chauvin, Prabakar Vaittinada Ayar, Arthur Bourg, Bruno Riou, Stephane Marot, Ben Bloom, Marine Cachanado, Tabassome Simon, Yonathan Freund, Maud Salmona, Jérôme Le Goff, David Veyer, Richard Chocron, Clément Augustin, Flore Rozenberg, Jean-François Meritet, Aurélie Schnuriger, Slim Fourati, Mehdi Khellaf, Audrey Coulomb, Frédéric Gindre, Khouloud Aloui, Hervé Jacquier, Xavier Eyer, Christophe Choquet, Vittiaroat Ing, Thomas Pavlovsky, Nadhira Houhou-Fidouh, Valentine Ferré, Luce Landraud, Hélène Goulet, Youri Yordanov, Laurence Berard, Alexandra Rousseau, Théophile Morel, Theophile Vieux, Simon Cahen, Melkir Saib, Maud Salmona, Jérôme Le Goff, David Veyer, Richard Chocron, Clément Augustin, Flore Rozenberg, Jean-François Meritet, Aurélie Schnuriger, Slim Fourati, Mehdi Khellaf, Audrey Coulomb, Frédéric Gindre, Khouloud Aloui, Hervé Jacquier, Xavier Eyer, Christophe Choquet, Vittiaroat Ing, Thomas Pavlovsky, Nadhira Houhou-Fidouh, Valentine Ferré, Luce Landraud, Hélène Goulet, Youri Yordanov, Laurence Berard, Alexandra Rousseau, Théophile Morel, Theophile Vieux, Simon Cahen, Melkir Saib
Journal: Annals of Internal Medicine (2022)

At the end of 2021, the B.1.1.529 SARS-CoV-2 variant (Omicron) wave superseded the B.1.617.2 variant (Delta) wave.To compare baseline characteristics and in-hospital outcomes of patients with SARS-CoV-2 infection with the Delta variant versus the Omicron variant in the emergency department (ED).Retrospective chart reviews.13 adult EDs in academic hospitals in the Paris area from 29 November 2021 to 10 January 2022.Patients with a positive reverse transcriptase polymerase chain reaction (RT-PCR) test result for SARS-CoV-2 and variant identification.Main outcome measures were baseline clinical and biological characteristics at ED presentation, intensive care unit (ICU) admission, mechanical ventilation, and in-hospital mortality.A total of 3728 patients had a positive RT-PCR test result for SARS-CoV-2 during the study period; 1716 patients who had a variant determination (818 Delta and 898 Omicron) were included. Median age was 58 years, and 49% were women. Patients infected with the Omicron variant were younger (54 vs. 62 years; difference, 8.0 years [95% CI, 4.6 to 11.4 years]), had a lower rate of obesity (8.0% vs. 12.5%; difference, 4.5 percentage points [CI, 1.5 to 7.5 percentage points]), were more vaccinated (65% vs. 39% for 1 dose and 22% vs. 11% for 3 doses), had a lower rate of dyspnea (26% vs. 50%; difference, 23.6 percentage points [CI, 19.0 to 28.2 percentage points]), and had a higher rate of discharge home from the ED (59% vs. 37%; difference, 21.9 percentage points [-26.5 to -17.1 percentage points]). Compared with Delta, Omicron infection was independently associated with a lower risk for ICU admission (adjusted difference, 11.4 percentage points [CI, 8.4 to 14.4 percentage points]), mechanical ventilation (adjusted difference, 3.6 percentage points [CI, 1.7 to 5.6 percentage points]), and in-hospital mortality (adjusted difference, 4.2 percentage points [CI, 2.0 to 6.5 percentage points]).Patients with COVID-19 illness and no SARS-CoV-2 variant determination in the ED were excluded.Compared with the Delta variant, infection with the Omicron variant in patients in the ED had different clinical and biological patterns and was associated with better in-hospital outcomes, including higher survival.None.