Abstract:
Objective To analyze the epidemic and death cases of human infection with highly pathogenic avian influenza (HPAI) A (H7N9) virus in the mainland of China from 2016 to 2018, and provide evidences for reducing the severity and disease burden of human infection with highly pathogenic avian influenza virus.
Methods Based on the existing surveillance data of human infection with HPAI A (H7N9) virus in China, descriptive epidemiological analysis was conducted on the time, area and population distributions of cases infected with HPAI A (H7N9) virus in China, and the epidemiologic and clinical characteristics of survival cases and death cases were compared.
Results Since December 2016, a total of 32 cases of human infection with HPAI A (H7N9) virus, including 13 deaths, had been reported from 8 provinces in China. The case fatality rate was 40.63%, the difference was not significant compared with the cases infected with low pathogenic avian influenza (LPAI) A (H7N9) virus (37.98%) (χ2=0.090, P=0.763). The median age of the cases was 59 years, and the male to female ratio of the cases was 1.67∶1. Up to 81.25% of the cases were farmers. There were no significant differences in population, time and area distributions as well as key time interval in the course of disease, exposure history and underlying medical condition between the survival cases and the death cases. The results showed that acute respiratory distress syndrome, renal failure, cardiac failure and septic shock might be the risk factors resulting the deaths of the cases of HPAI A (H7N9) virus infection.
Conclusion The case fatality rate of human infection with HAPI A (H7N9) virus in the mainland of China was relatively high during 2016–2018. The occurrence of specific clinical manifestations and complications might predict the severe outcomes. It is necessary to strengthen the research and training on clinical diagnosis and treatment of human infection with highly pathogenic avian influenza virus in order to alleviate the severity of the disease.