Clinical Diagnosis of Influenza.

Accurate diagnosis of influenza is critical for clinical management, infectious control, and public health actions to minimize the burden of disease. Rapid influenza diagnostic tests can detect circulating influenza viruses within 10-15 min and are widely used in clinical practice for diagnosing influenza. The sensitivity of rapid influenza diagnostic tests is relatively low at 50-70%, and such tests are only available for the diagnosis of circulating viruses. Reverse transcription polymerase chain reaction (RT-PCR) is a representative molecular assay with very high sensitivity and specificity. This technique takes several hours, is labor intensive, and requires a specific instrument. The cell culture method is necessary for surveillance and can provide information regarding the emergence of drug resistance, minor antigenic variation of the virus, and a pandemic virus. However, it is not suitable for clinical decisions because it takes several days or longer to obtain a positive result.