How can a complete blood count (CBC) diagnose influenza A and B?

Influenza A and B are acute infectious diseases caused by influenza A and B viruses, falling within the category of epidemic influenza. Co-infection with both viruses often leads to more severe illness. The primary diagnostic method for confirming influenza A and B is a complete blood count (CBC). In CBC results, an elevated ratio of nucleated cells (white blood cells, lymphocytes, neutrophils), a total white blood cell count (WBC) above 3.5 × 10⁹/L, reduced hematocrit (Hct), hemoglobin (Hb) levels between 120–150 g/L, decreased platelet count (PLT), and a platelet count within the range of 100–300 × 10⁹/L can provide meaningful diagnostic clues, helping assess the patient's condition and guide appropriate treatment. Additionally, viral detection through methods such as nasopharyngeal swabs or serological testing can confirm the diagnosis of influenza A and B.