Clinical features of COVID-19 and influenza: A comparative study on Nord Franche-Comte cluster

Zayet, Souheil; Kadiane-Oussou, N’dri Juliette; Lepiller, Quentin; Zahra, Hajer; Royer, Pierre-Yves; Toko, Lynda; Gendrin, Vincent; Klopfenstein, Timothée

Clinical descriptions about influenza-like illnesses (ILI) in COVID-19 seem non-specific. We aimed to compare the clinical features of COVID-19 and influenza. We retrospectively investigated the clinical features and outcomes of confirmed cases of COVID-19 and influenza in Nord Franche-Comté Hospital between February 26(th) and March 14(th) 2020. We used SARS-CoV-2 RT-PCR and influenza virus A/B RT-PCR in respiratory samples to confirm the diagnosis. We included 124 patients. The mean age was 59(±19[19-98]) years with 69% female. 70 patients with COVID-19 and 54 patients with influenza A/B. Regarding age, sex and comorbidities, no differences were found between the two groups except a lower Charlson index in COVID-19 group (2[±2.5] vs 3[±2.4],p=0.003). Anosmia (53% vs 17%,p<0.001), dysgeusia (49% vs 20%,p=0.001), diarrhea (40% vs 20%,p=0.021), frontal headache (26% vs 9%,p=0.021) and bilateral cracklings sounds (24% vs 9%,p=0.034) were statistically more frequent in COVID-19. Sputum production (52% vs 29%,p=0.010), dyspnea (59% vs 34%,p=0.007), sore throat (44% vs 20%,p=0.006), conjunctival hyperhemia (30% vs 4%,p<0.001), tearing (24% vs 6%,p=0.004), vomiting (22% vs 3%,p=0.001) and rhonchi sounds (17% vs 1%,p=0.002) were more frequent with influenza infection. We described several clinical differences which can help the clinicians during the co-circulation of influenza and SARS-CoV-2.