1960s Nurse Handling Test Tubes

Ms. Beverly Lawrence, former Administrative Assistant in the Respiratory Virus Infections Unit at the Centers for Disease Control and Prevention, was shown here in this 1968 photograph handling test tubes containing frozen throat swab specimens that were to be tested for influenza.

Because the symptoms of influenza can be similar to those caused by other infectious agents, the disease can be difficult to diagnose based on clinical symptoms alone. A number of tests can help in the diagnosis of influenza, but testing does not need to be done for all patients. During an outbreak of respiratory illness, testing for influenza can help determine if influenza is the cause of the outbreak.