Testing for swine flu involves the use of a specialized laboratory test, commonly referred to as the PCR, or polymerase chain reaction, test. This test generally require several days to one week before results are determined. Most doctors reserve the use of the PCR test for pregnant women, people who have been hospitalized with the flu, or people who have compromised immune systems and are at increased risk for serious flu complications. The PCR test is the only kind of flu test that can diagnose swine flu specifically, and it is done by comparing samples of DNA taken from a flu-infected person to the genetic makeup of the swine flu virus. The majority of people who are suspected to have swine flu do not receive this test and instead may be diagnosed either based on their symptoms or through a rapid influenza diagnostic test.
The rapid flu diagnostic test is the flu test most doctors use. It cannot always differentiate between specific flu strains, and it is not used in testing for swine flu, but it can often positively detect the presence of the influenza virus approximately 10 to 70 percent of the time. The test is usually performed using a swab that is inserted inside the nose or into the mouth to get a sample from the nasal passage or from the back of the throat. After the sample is retrieved, doctors can test it in a lab and have the results back usually within 30 minutes. If the results are positive, doctors normally prescribe antiviral medication and send their patients home with instruction to get lots of rest and to drink plenty of fluids.
Even though the rapid flu diagnostic test cannot determine the presence of swine flu precisely, as of 2011 doctors still often assume that their patients have swine flu if the results of this test come back positive. The reason for this is because the swine flu pandemic, which began in 2009, has been so widespread that doctors conclude the majority of people probably have the swine flu if they are diagnosed with influenza. The treatment for swine flu and other types of influenza are generally the same, and for this reason doctors normally do not concern themselves with testing for swine flu specifically in most people if they are otherwise healthy.
Some doctors do not bother with testing for swine flu or other types of flu, and may instead diagnose swine flu based on their patient's symptoms. The reason for this is probably because of how widespread swine flu has been since it became a concern in 2009. Instead of bothering with the PCR test or with the rapid flu diagnostic test, many doctors ask their patients about their symptoms and diagnose them with swine flu if the symptoms seem to match up with the illness. All types of flu, including swine flu, generally have to run their course, and doctors normally prescribe antiviral medicine to their patients to help speed up recovery time.