Rapid Flu Testing
Influenza, commonly known as the flu, is an upper respiratory viral infection that affects the nose, throat, air passages, and lungs. Because if it highly contagious, the flu is an annual epidemic illness that, in spite of the administration of flu vaccines, strikes millions of people in the United States each year, causing much misery and some serious, even fatal, complications. Flu symptoms often mimic those of other upper respiratory infections. In the past, doctors had to depend on their ability to distinguish the flu from other illnesses based on patient symptoms alone. In recent years, however, rapid flu testing has become available.
A rapid flu test can help determine the type and severity of the flu virus. To test for the flu, a swabbed sample is taken from either the nose or the back of the throat of the patient. When a rapid flu test is administered, results are available within only 15 minutes, right at the doctor's office. Although laboratory flu tests have been available for some time, previous tests took much longer to provide results. Because the treatment that can greatly shorten the duration of the illness is most effective when administered within the first 48 hours, early diagnosis of the flu is essential.
Benefits of Rapid Flu Testing
Flu tests can identify both the influenza A and influenza B viruses. If the results of the rapid flu test are positive, indicating the presence of the flu, the doctor can prescribe antiviral medication to treat symptoms and to lessen the severity and length of the illness. Taking this measure also limits the spread of the virus. For these reasons, the rapid flu test is a tremendous advancement both for the individual patient in terms of symptom relief and avoidance of complications, and for the community in general in terms of limiting contagion.
In addition, by distinguishing the flu virus from other upper respiratory infections that may be bacterial, the inappropriate use of antibiotics is reduced, an important step toward preventing mutations that result if the development of drug-resistant strains of bacteria.
Types of Rapid Flu Testing
There are several types of rapid influenza diagnostic tests (RIDTs) no available, all of which can provide results within 15 minutes. More than 10 have been approved the FDA. There are some important distinctions between varieties of RIDTs; among these are the fact that some RIDTs can identify both A and B viruses and distinguish between them, and some cannot.
Accuracy of Rapid Flu Testing Results
The accuracy of the different types of RIDTs may vary according to whether the specimen obtained has been collected via throat swab or nasal swab. In addition, the accuracy of these rapid flu tests may depending on how widespread the influenza outbreak is in the community. In general, during the height of the flu season, typically between November and January, false negatives can occur as frequently as 40 percent of the time, but false positive test results are unlikely. At the beginning and end of the flu season, however, when the illness is less prevalent, false positive results are more common and negative results are more likely to be accurate.