Comparison of patients hospitalized with COVID-19, H7N9 and H1N1

Abstract

Background: There is an urgent need to better understand the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for that the coronavirus disease 2019 (COVID-19) continues to cause considerable morbidity and mortality worldwide. This paper was to differentiate COVID-19 from other respiratory infectious diseases such as avian-origin influenza A (H7N9) and influenza A (H1N1) virus infections.

Methods: We included patients who had been hospitalized with laboratory-confirmed infection by SARS-CoV-2 (n = 83), H7N9 (n = 36), H1N1 (n = 44) viruses. Clinical presentation, chest CT features, and progression of patients were compared. We used the Logistic regression model to explore the possible risk factors.

Results: Both COVID-19 and H7N9 patients had a longer duration of hospitalization than H1N1 patients (P < 0.01), a higher complication rate, and more severe cases than H1N1 patients. H7N9 patients had higher hospitalization-fatality ratio than COVID-19 patients (P = 0.01). H7N9 patients had similar patterns of lymphopenia, neutrophilia, elevated alanine aminotransferase, C-reactive protein, lactate dehydrogenase, and those seen in H1N1 patients, which were all significantly different from patients with COVID-19 (P < 0.01). Either H7N9 or H1N1 patients had more obvious symptoms, like fever, fatigue, yellow sputum, and myalgia than COVID-19 patients (P < 0.01). The mean duration of viral shedding was 9.5 days for SARS-CoV-2 vs 9.9 days for H7N9 (P = 0.78). For severe cases, the meantime from illness onset to severity was 8.0 days for COVID-19 vs 5.2 days for H7N9 (P < 0.01), the comorbidity of chronic heart disease was more common in the COVID-19 patients than H7N9 (P = 0.02). Multivariate analysis showed that chronic heart disease was a possible risk factor (OR > 1) for COVID-19, compared with H1N1 and H7N9.

Conclusions: The proportion of severe cases were higher for H7N9 and SARS-CoV-2 infections, compared with H1N1. The meantime from illness onset to severity was shorter for H7N9. Chronic heart disease was a possible risk factor for COVID-19.The comparison may provide the rationale for strategies of isolation and treatment of infected patients in the future.

Keywords: COVID-19; Comparison; H1N1; H7N9; SARS-CoV-2.

Fig. 1

a Distribution of the number of days of hospitalization for patients with COVID-19, H7N9 and H1N1. b The days from illness onset to severity for severe patients with COVID-19 and H7N9. COVID-19: Coronavirus disease 2019, H7N9: avian-origin influenza A (H7N9) virus, H1N1: influenza A (H1N1) virus

Fig. 2

Case fatality risk and invasive ventilation risk in hospitalized patients. a Days from hospitalization to death. b days from illness onset to death. c Days from hospitalization to tracheal intubation. d Days from illness onset to tracheal intubation. e Days from hospitalization to mechanical ventilation. f Days from illness onset to mechanical ventilation

Fig. 3

a–c Chest CT Images of a 36-year-old man with COVID-19 on admission, showed multiple ground-glass densification shadows with multiple diffusions in both lungs, mainly distributed under the pleura. d–f Chest CT Images of a 32-year-old man infected with H7N9 on admission, showed multilobar patchy consolidation and diffuse alveolar opacities. g–i Chest CT Images of a 29-year-old woman infected with H1N1 on admission, showed ground-glass opacity and small patchy shadows with diffused distribution in the right middle and lower lungs