Rapid influenza diagnostic tests (RIDTs) are a simple way of obtaining assay results, are low cost, and produce results quickly, at less than 30 minutes, so they are commonly used, but they cant distinguish between IAV and IBV or between IAV subtypes and are not as sensitive as nucleic-acid based tests.Nucleic acid-based tests (NATs) amplify and detect viral nucleic acid. Most of these tests take a few hours, but rapid molecular assays are as fast as RIDTs. Among NATs, reverse transcription polymerase chain reaction (RT-PCR) is the most traditional and considered the gold standard for diagnosing influenza because it is fast and can subtype IAV, but it is relatively expensive and more prone to false-positives than cultures. Other NATs that have been used include loop-mediated isothermal amplification-based assays, simple amplification-based assays, and nucleic acid sequence-based amplification. Nucleic acid sequencing methods can identify infection by obtaining the nucleic acid sequence of viral samples to identify the virus and antiviral drug resistance. The traditional method is Sanger sequencing, but it has been largely replaced by next-generation methods that have greater sequencing speed and throughput. Treatment
Treatment of influenza in cases of mild or moderate illness is supportive and includes anti-fever medications such as acetaminophen and ibuprofen, adequate fluid intake to avoid dehydration, and resting at home. Cough drops and throat sprays may be beneficial for sore throat. It is recommended to avoid alcohol and tobacco use while sick with the flu. Aspirin is not recommended to treat influenza in children due to an elevated risk of developing Reye syndrome.
Influenza viruses, particularly IAV, evolve quickly, so flu vaccines are updated regularly to match which influenza strains are in circulation. Vaccines currently in use provide protection against IAV subtypes H1N1 and H3N2 and one or two IBV subtypes. Influenza infection is diagnosed with laboratory methods such as  antibody or antigen tests and a polymerase chain reaction (PCR) to identify viral nucleic acid. The disease can be treated with supportive measures and, in severe cases, with antiviral drugs such as oseltamivir. In healthy individuals, influenza is typically self-limiting and rarely fatal, but it can be deadly in high-risk groups. In a typical year, 5–15% of the population contracts influenza. There are 3–5 million severe cases annually, with up to 650,000 respiratory-related deaths globally each year. Deaths most commonly occur in high-risk groups, including young children, the elderly, and people with chronic health conditions. In temperate regions of the world, the number of influenza cases peaks during winter, whereas in the tropics influenza can occur year-round. Since the late 1800s, large outbreaks of novel influenza strains that spread globally, called pandemics, have occurred every 10–50 years. Five flu pandemics have occurred since 1900: the Spanish flu in 1918–1920, which was the most severe flu pandemic, the Asian flu in 1957, the Hong Kong flu in 1968, the Russian flu in 1977, and the swine flu pandemic in 2009. Signs and symptoms
The time between exposure to the virus and development of symptoms, called the incubation period, is 1–4 days, most commonly 1–2 days. Many infections, however, are asymptomatic.