Objective To understand the epidemiological characteristics of an epidemic of human infection with avian influenza A(H7N9)virus in Yunnan province and provide evidence for the prevention and control of human infection with avian influenza in the future.Methods A field epidemiological survey was conducted among patients and close contacts and in live-poultry markets.The samples collected from the patients and outdoor environment were detected and analyzed.Results During June-July 2017,five confirmed cases of...