Influenza type B viruses belong to either B/Yamagata or B/Victoria lineage. Influenza C virus is detected less frequently and usually causes mild infections, thus does not present public health importance. Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people. Signs and symptoms

Dec 2, 2024 · What is influenza (the flu)? The flu is a viral infection of the lungs and airways. The virus spreads ...

Oct 16, 2024 · Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. It is characterized by a sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose. The cough can be severe and can last two or more weeks.

Sep 12, 2024 · This WHO Clinical practice guideline for influenza is an update and expansion from the previously published WHO guideline on the clinical management of patients with severe influenza or at risk of severe influenza. These updated guidelines provide recommendations on the management of both severe and non-severe influenza and also includes recommendations on the use of antiviral medications to ...

Influenza, or the flu, is both a seasonal and a pandemic virus. Every year, mainly during the winter season, seasonal influenza infects as many as 1 billion people. This makes it one of the most common infectious respiratory viruses, after the common cold. Thankfully, the WHO Global Influenza Surveillance and Response System, or GISRS, monitors what viruses are circulating and twice a year ...

Nov 27, 2009 · Influenza is usually mild and uncomplicated and most people recover without medical treatment. However infection with influenza may occasionally cause severe disease and death, particularly among the elderly, pregnant women, very young children and persons with certain medical conditions (including chronic heart, lung, kidney, liver, blood or ...

Influenza pandemics have occurred throughout history: records document at least 3 well before the 1918–19 pandemic, and another 3 have taken hold after, in 1957–58, 1968–69 and 2009–10. Influenza viruses with pandemic potential regularly emerge, but not all …

Since 2004, influenza A(H5N1), A(H9N2) and other subtypes of influenza viruses have also been taken into consideration by GISRS for pandemic preparedness purposes. The development of high yield candidate vaccine viruses is a complex process, involving collaboration of laboratories involved in developing reassortants and WHO Collaborating ...

Jan 9, 2025 · Influenza (flu) is a respiratory illness caused by influenza viruses that spreads easily through close contact with an infected person. The virus can be passed on from an infected person’s mouth or nose in droplets when they speak, cough and sneeze.

Oct 3, 2023 · Influenza A viruses are established in many animal species. The emergence of an influenza A virus, with the ability to infect people and sustain human-to-human transmission, could cause an influenza pandemic. Influenza type A viruses are classified into subtypes according to the combinations of the proteins on the surface of the virus.