The SARS-CoV-2 Omicron variant of concern (VOC) was first identified in South Africa during November 2021, and has now become the dominant variant in Europe and worldwide. However, as the number of Omicron COVID-19 cases increased rapidly in South Africa, the rate of hospitalization due to Omicron infections seemed lower than that of Delta infections.

The Greater Paris area has experienced five COVID-19 surges. We aimed to assess the impact and clinical severity of patients infected during the Omicron surge compared with the previous surges in community setting in this area.

We performed a cohort study including adult patients, with confirmed COVID-19 diagnosis (RT-PCR or antigen), managed from 9 March 2020 until 11 January 2022 with Covidom, a telesurveillance solution for home monitoring of patients with COVID-19 in the greater Paris area. When included, the patients completed on a daily basis self-administered questionnaires until 10 to 30 days according to symptom course. According to predefined thresholds, questionnaires could generate 2 types of alerts: orange alert (mild priority), and red alert (top priority alert). Outcome was recorded: unplanned hospitalization (including in intensive care unit), contact with national emergency number, or admission to Emergency department.

Overall, 225,248 patients were included in the study, including 72,394 from the last surge, which is more numerous compared to the previous surges. Patients included during the Delta and Omicron waves were younger (mean age 35.6 ± 13.0 and 38.4 ± 13.0 versus maximum 44.5 ± 14.5 years in surge 1; p<0.001). Significantly fewer patients with comorbidities were included in surge 5 (p<0.001), and the proportion presenting with respiratory signs was lower (49.8% in surge 5 vs maximum 86.5% in surge 1; p<0.001). During surge 5, while the number of patients included was high compared to previous surges, the rate of orange and red alerts was significantly lower (p<0.0001), as the number of hospitalizations, national emergency contact and emergency unit requirement (p<0.0001).

These data confirm that the Omicron surge is highly significant considering the number of cases but presents with a low rate of severe presentation and worsening.

Aucun lien d'intérêt