How Is Influenza Diagnosed?
Influenza is typically diagnosed based on a combination of clinical symptoms and diagnostic testing. When a patient presents with symptoms suggestive of influenza, such as sudden fever, cough, and muscle aches, a healthcare provider may perform a physical examination and review the patient's medical history. During flu season, the presence of these symptoms might be enough to diagnose influenza, especially if there is a known outbreak in the community.
For a definitive diagnosis, a healthcare provider may order laboratory tests. The most common test is the rapid influenza diagnostic test (RIDT), which can detect influenza antigens in respiratory secretions and provide results within 15 minutes. However, these tests are not always accurate, particularly in adults. More sensitive tests, such as reverse transcription-polymerase chain reaction (RT-PCR), can confirm the presence of the influenza virus and identify its subtype. These tests are more accurate but may take longer to produce results. In certain cases, such as during a severe outbreak or in hospitalized patients, more extensive testing might be performed to guide treatment and public health responses.