Epidemiological and clinical characteristics of human infections with avian influenza A (H7N9) and A (H5N6) viruses in Guangdong province, 2013-2018

Abstract

Objective To analyze the epidemiological and clinical characteristics of human infections with avian influenza A (H7N9) and A (H5N6) viruses between 2013 and 2018 in Guangdong province. Methods The confirmed human infections cases of avian influenza viruses reported between 2013 and 2018 were used as research subjects. The basic information, disease distribution, exposure history, disease clustering and clinical characteristics were analyzed by statistical methods. Results A total of 259 human infection cases of influenza A (H7N9) virus were confirmed with the fatality rate of 38.6%. Eight human infection cases of influenza A (H5N6) were confirmed with the fatality rate of 62.5%. Most of the cases occurred from November to April and in the Pearl River Delta. The cases of influenza A (H7N9) virus infection were more common in male patients while the cases of influenza A (H5N6) infections were more common in female patients. Direct or indirect exposure to live poultry were obsevered in 245 influenza A (H7N9) virus infection cases (94.6%) and 7 influenza A (H5N6) virus infection cases (87.5%). There were six clusters of influenza A (H7N9) virus infection cases in Guangdong province. Regarding the clinical severity, most of the cases were severe, and the median value of time interval from onset to oseltamivir treatment were more than five days. Conclusions The epidemiological and clinical characteristics of humans infections with avian influenza A (H7N9) and A (H5N6) viruses were different in Guangdong province. Early detection and intervention of humans infections with different subtypes of avian influenza viruses should be enforced to prevent and control the spreading and epidemics of human infections with avian influenza viruses. Key words: Humans humans infections with avian influenza viruses; H7N9; H5N6; Epidemiological characteristics