Diagnosis and differential diagnosis I. Diagnosis. The diagnosis of human H7N9 avian influenza can be made based on the epidemiological contact history, clinical manifestations and laboratory test results. In the case of unknown epidemiological history, the diagnosis of human infection with H7N9 avian influenza can be made based on clinical manifestations, auxiliary examinations and laboratory test results, especially if H7N9 avian influenza virus is isolated from the patient’s respiratory secretion specimen, or if the nucleic acid test for H7N9 avian influenza virus is positive, or if the level of specific antibodies to the H7N9 avian influenza virus is four times or more elevated in the dynamic test double serum. 1, epidemiological history. History of contact with birds and their secretions and excretions within 1 week before the onset of the disease. 2, diagnostic criteria. (1) Suspected cases: consistent with the above clinical manifestations, positive for influenza A virus antigen, or a history of epidemiological exposure. (2) confirmed cases: consistent with the above clinical manifestations, or a history of epidemiological exposure, and the isolation of H7N9 avian influenza virus in respiratory secretion specimens or H7N9 avian influenza virus nucleic acid test positive or dynamic detection of double serum H7N9 avian influenza virus-specific antibody level is four times or more elevated. Severe cases: pneumonia combined with respiratory failure or other organ failure is a severe case. Second, differential diagnosis. Attention should be paid to the differential diagnosis of human infection with highly pathogenic H5N1 avian influenza, seasonal influenza (including influenza A (H1N1)), bacterial pneumonia, infectious atypical pneumonia (SARS), novel coronavirus pneumonia, adenovirus pneumonia, chlamydial pneumonia, mycoplasma pneumonia and other diseases. The differential diagnosis mainly relies on pathogenetic examination. Treatment 1.Patients with clinical diagnosis and confirmed diagnosis should be treated in isolation. 2, symptomatic treatment. Oxygen, antipyretics, cough expectorants, etc. can be applied. 3.Anti-viral treatment. Anti-influenza virus drugs should be applied as early as possible.