Objective To analyze the epidemiological characteristics of the first case of human infection with H7N9 avian influenza in Gansu province, and to provide scientific basis for the prevention and control of H7N9 avian influenza.
Methods The epidemiological investigation method was used to investigate the incidence and treatment, possible infection sources, transmission routes and exposure factors of the first human case of H7N9 infection in Gansu province, medical investigation was also conducted for close contacts, and external environmental samples were collected for detection. Moreover, we initiated disinfection of the epidemic area.
Results The first case of human infection with H7N9 avian influenza confirmed in Gansu province was an 82-year-old male urban resident. He went to a private clinic for cough on March 29, and went to Jiuquan City Hospital on April 3 for treatment. The patient had a history of activities near the live poultry sales store where H7N9 virus nucleic acid was tested positive, The positive test result of H7N9 avian influenza virus nucleic acid detected from pharynx swab was consistent with those of the Provincial and National Centers for Disease Control and Prevention. The case was carefully treated and cured 17 days after the onset. Nine close contacts underwent a 7 days medical health observation, which did not show any health abnormalities. A total of 357 flu-like cases and unexplained pneumonia and 2 cases who were H7N9 avian influenza virus nucleic acid positive were reported in the city. Three cases of H7N9 found in Jiuquan city had a history of exposure to the live poultry market, and one of them died due to late diagnosis.
Conclusions Exposure to the external environment of H7N9 avian influenza virus is the main risk factor of H7N9 infection in humans. The management of free-range poultry and live poultry market should be strengthened, especially the circulation management of live poultry. The monitoring of external environment for avian influenza plays an important role in the prevention and control of human infection with h7n9 avian influenza.