How to distinguish between type A and type B influenza

Influenza A and B refer to two subtypes of infectious epidemic viral diseases. Influenza A, also known as typical mumps, is an acute epidemic infectious disease caused by the type A mumps virus. Typical symptoms of type A mumps virus infection include mild fever, headache, oral or pharyngeal symptoms, and general fatigue; however, in atypical cases, there may be an intermittent phase or high fever accompanied by lymph node swelling. Influenza B, primarily caused by the Japanese encephalitis virus, is an acute epidemic infectious disease characterized clinically by fever, headache, sore throat, neurological dysfunction, possible mild limb movement disorders, and sometimes psychiatric symptoms or muscle spasms. Differentiation between influenza A and B can be achieved through laboratory tests, such as serum detection of epidemic viral antibodies and antigens, nucleic acid testing for type A and B mumps viruses, and detection of viral antibodies in cerebrospinal fluid. Comparative analysis of these results allows accurate distinction between the two. Clinical manifestations can also serve as a reference, but clinicians should remain alert to rare cases of mixed infection involving both types.