Some studies have shown that flu throat swabs are about 50% accurate.
The influenza throat swab test uses a pharyngeal swab to collect secretions from the throat and detects the presence of influenza antigens to determine whether or not one is infected with influenza. Since the throat is affected by swallowing, the accuracy is relatively lower, and in the early stages of influenza, the number of influenza viruses in the throat is low and not always detectable.
To improve the accuracy of the test, nasopharyngeal secretions can be collected. Nasopharyngeal secretions have a higher number of viruses compared to the pharynx and are less susceptible, resulting in a higher detection rate, but are less comfortable for the patient to handle. A positive influenza nasopharyngeal swab generally indicates infection with the influenza virus and requires antiviral and other treatments.
Patients should seek prompt medical attention to clarify the diagnosis and follow medical advice.