How to determine whether it is influenza A or influenza B virus

The diagnosis of influenza A and influenza B viruses generally requires the following: 1. Epidemiological history: exposure to patients with influenza A or influenza B, or development of typical clinical symptoms during peak influenza seasons, which raises suspicion for possible influenza A or B infection. 2. Clinical symptoms: acute onset of illness accompanied by high fever, headache, muscle aches, as well as nasal discharge, sneezing, and related symptoms, consistent with the clinical features of influenza A and influenza B. 3. Etiological testing: if a patient exhibits the aforementioned characteristics of influenza A or B, and repeated nucleic acid tests or antigen tests for influenza A or influenza B return positive results, a definitive diagnosis of influenza A or influenza B can be established.