Comparison of the clinical features and outcomes of severe seasonal influenza and COVID-19 patients in Tunisia between 2021 and 2022.

BACKGROUND: We compared patients diagnosed at a SARI (severe acute respiratory infections) surveillance site with COVID-19 and those with seasonal influenza to investigate the clinical differences, common features, and outcomes.

METHODS: We conducted a descriptive, retrospective study in the Medical Intensive Care Unit (ICU) at Abderrahman Mami Hospital between September 2021 and April 2022. Demographic, clinical, and biological data as well as outcomes were recorded for all patients.

RESULTS: Among 223 SARI patients, 83 were confirmed COVID-19, and 22 were influenza positive. The distribution according to gender was similar; but patients with influenza were younger than those suffering from COVID-19(mean age 60.36 SD 17.28 vs. 61.88 SD 17.91; P = 0.601). In terms of underlying chronic diseases, the frequency was 84.3% in the COVID-19 group and 72.7% in the influenza group. COVID-19 patients had a longer duration of hospitalization (mean [SD], 9.51 days [8.47 days] vs. 7.33 days [8.82 days]; P = 0.003), and a more frequent need for invasive ventilation (80 [97.4%] vs. 20 [92.3]). Case fatality was also higher among this group compared to the latter (39 [47%] vs. 6 [27.3%], P = 0.01).

CONCLUSION: This exploratory study suggests higher severity of COVID-19 compared to seasonal influenza among SARI hospitalized patients even during the Omicron wave. Further research on higher sample sizes is required to confirm this conclusion.