Novel Avian-Origin Influenza A (H7N9) in Critically Ill Patients in China*

Abstract

OBJECTIVES: In March 2013, human infection with a novel avian-origin reassortment influenza A (H7N9) virus was identified in China. A total of 26 cases were confirmed and treated in Jiangsu. All the patients had findings consistent with pneumonia and were admitted to an ICU, which pose a threat to human health. We aimed to provide the clinical features, treatment, and prognosis of the critically ill patients with H7N9 viral infection. DESIGN: A retrospective cohort study. SETTING: Eight closed ICUs in general hospitals distributed throughout the Jiangsu Provincial, China. PATIENTS: Patients infected with influenza A (H7N9) virus from March 20, 2013, through May 1, 2013, in Jiangsu Province were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twenty-seven patients infected with H7N9 virus were identified in Jiangsu. Of these, 26 were hospitalized. The median age was 54.5 years, and 18 patients (69.2%) were men. The most common symptoms at the onset of illness were high fever and cough. White cell counts were normal or decreased. All the patients had findings consistent with pneumonia. Twenty-four patients (92.3%) developed acute respiratory distress syndrome, and 10 (38.5%) developed septic shock quickly after the onset of illness. Treatment with antiviral drugs was initiated in all the patients at a median of 8 days after the onset of illness. Mortality was 19.2% at 28 days and 30.8% at 90 days. Based on multiple logistic regression analysis, septic shock associated with severe hypoxemia was the only independent risk factor for mortality. CONCLUSIONS: Infection with novel avian-origin reassortment influenza A (H7N9) virus is characterized by high fever, cough, and severe respiratory failure and is associated with a high mortality. These data provide some general understandings for the early identification, ICU treatment, and short-term prognosis of hospitalized critical patients with H7N9.