ObjectiveTo investigate epidemiological risk factors for humans infected with avian influenza A (H7N9) virus and provide scientific evidence for future prevention and control of this disease.

MethodsDescriptive epidemiological analysis was made by using information on cases of humans infected with H7N9 avian influenza reported by "Disease Monitoring Information Report Management System", and in combination with case questionnaire and epidemiological survey data and others.

ResultsA total of seven human cases of avian influenza A (H7N9) were reported in Cixi City from January 2014 to May 2017, of which one was fatal, six had close contact with live poultry and one had exposure to poultry stall in farm market prior to the illness onset. Positive rate of nucleic acid of H7N9 virus for environment specimen 7 cases contacted was 55.6%, and detection positive rate for environment specimen from farm markets in Cixi City was 38.4% in January 2014 and 64.3% in December 2016 to February 2017.All specimens from live poultry at local poultry farm were negative.

ConclusionPoultry trade markets and live poultry stalls prove to be high risk sites for virus infection. In order to prevent the occurrence of human avian influenza A (H7N9), seasonal market closure should be implemented, management of poultry trade market enhanced, hygiene management and sterilization for poultry trade market standardized, and mobile poultry vendors restrained. At the same time, preventive knowledge education for residents and protection for occupational groups should be intensified.