Influenssaviruksilta

Influenssaviruksilta are viruses that cause influenza, commonly known as the flu. They belong to the family Orthomyxoviridae. There are four main types of influenza viruses: A, B, C, and D. Influenza A and B viruses are responsible for seasonal epidemics in humans. Influenza C viruses cause mild respiratory illness and do not cause epidemics. Influenza D viruses primarily affect cattle.

Influenza viruses are RNA viruses with a segmented genome. Their surface proteins, hemagglutinin (HA) and neuraminidase (NA), are important for classification and are targets for the immune system. The rapid mutation rate of influenza viruses, particularly type A, is a key reason for the need for annual flu vaccines. These viruses are spread through respiratory droplets produced when an infected person coughs, sneezes, or talks.

Symptoms of influenza typically include fever, cough, sore throat, body aches, headaches, and fatigue. While most people recover within a week or two, influenza can lead to severe complications, such as pneumonia, bronchitis, and sinus infections, and can be fatal, especially in young children, older adults, pregnant women, and individuals with certain chronic health conditions. Antiviral medications can be used to treat influenza, but their effectiveness is greatest when started early in the illness. Prevention through vaccination is a cornerstone of public health efforts against influenza.