Influenza A virus subtype H1N1 - Wikipedia
Influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus (IAV). Some human-adapted strains of H1N1 are endemic in humans and are one cause of seasonal influenza …
H1N1 flu (swine flu) - Symptoms and causes - Mayo Clinic
Mar 23, 2023 · The H1N1 flu, sometimes called swine flu, is a type of influenza A virus. During the 2009-10 flu season, a new H1N1 virus began causing illness in humans. It was often called …
Swine Flu (H1N1): What Is It, Causes, Treatments & Prevention
Aug 5, 2022 · Swine flu (H1N1) is an infection that a type of flu (influenza) virus causes. It’s called swine flu because it’s similar to a flu virus that affects pigs (swine).
H1N1 Flu Virus (Swine Flu): Symptoms, Causes, Tests, and ...
Apr 30, 2025 · WebMD explains the H1N1 flu virus (swine flu), what causes it, and its symptoms, tests, treatments, and prevention.
Influenza A H1N1 | Symptoms, Treatment & Prevention | Britannica
Nov 28, 2025 · influenza A H1N1, virus that is best known for causing widespread outbreaks, including epidemics and pandemics, of acute upper or lower respiratory tract infection. The …
Influenza A (H1N1) outbreak - World Health Organization (WHO)
After early reports of influenza outbreaks in North America in April 2009, the new influenza virus spread rapidly around the world. By the time WHO declared a pandemic in June 2009, a total …
About Swine/Variant Flu | Swine Flu | CDC
Jul 8, 2024 · Human infections with H1N1v, H3N2v and H1N2v viruses have been detected in the United States. CDC data on the most current case counts for variant flu virus infections in …