Detection of H3N2 influenza can generally be done through peripheral blood test, viral nucleic acid test, virus isolation, and serum antibody test. 1. Peripheral blood test: through taking peripheral blood for routine blood test, the total number of white blood cells will be low or reduced, lymphocytes will be partially elevated, and the neutrophil count is usually normal; however, the percentage and absolute value of neutrophils can be reduced in severe patients. 2. Nucleic acid test: By detecting the upper respiratory tract secretions of H3N2 influenza patients, using pharyngeal swabs or nasal swabs, etc. to collect and immediately send for testing. By detecting the nucleic acid of H3N2 influenza virus, if the result is positive, it can be diagnosed as acute phase infection. 3. Virus isolation: A variety of means are commonly used to isolate and culture influenza viruses, by which the H3N2 influenza virus can be isolated from respiratory secretions. 4. Serum antibody test: After the virus invades the human body, the human immune system will produce a large number of immunoglobulins, the most common of which are IgG and IgM, and the test can find that the titer of specific antibody against the H3N2 influenza virus rises.