What is the Flu?
Flu is a seasonal, common, contagious respiratory illness caused by a virus called influenza, which is often mistaken for the common cold.
Influenza Virus Types
There are three main types of influenza viruses; Influenza A, Influenza B and Influenza C.Type C causes very mild infection, while types A and B it causes seasonal influenza that spreads rapidly among people every year. However, it is the Influenza A virus that causes the most common epidemics.
These viruses are divided into different subtypes (strains) according to the types of proteins (Hemagglutinin and Neuroaminidase) found on them. According to the types of these proteins indicated by the letters H and N, the virus strains are referred to by different names such as H1N1, H3N2, H1N2. For example, the influenza virus responsible for the swine flu epidemic that emerged in 2009 is the Influenza A H1N1 virus. Another characteristic of influenza viruses is that they mutate rapidly and change themselves every year.
Flu Symptoms and Duration of Sickness
The disease starts suddenly. Chills, chills, headache and muscle aches, cough, sore throat, watery eyes, nasal congestion manifests itself as mild discharge. Although it passes in a week in healthy people; Treatment takes longer for people with chronic diseases (such as diabetes, chronic kidney failure patients), the elderly, children and pregnant women. This disease is responsible for the deaths of an average of 36,000 people annually in the USA, even more than deaths caused by this cancer (Breast cancer: 40,000 people, Prostate cancer: 27,000 people).
Current Influenza Incidence and Strains
Due to seasonal variations every year, alarm bells may be heard when certain countries are followed. Since these countries spend the winter season before the rest of the world, the strains seen in them are seen as the dominant strain in the rest of the world. Australia is one of these countries. In Australia, which had a very bad year, the cases seen in the winter months of 2017 (June, July, August because it is in the Southern hemisphere) increased 2.5 times compared to the same period of the previous year and mainly H3N2 strain was detected. The H3N2 strain is a virus subtype not found in humans but seen in pigs. When it is generally seen in humans, it causes pandemic.
Ways to Avoid the Flu
The most effective way to prevent the flu is vaccination. Flu vaccine significantly reduces hospitalizations and mortality rates due to seasonal flu. The vaccine should be administered in September-October or at the latest in November. Since the antigenic structure of the flu virus is constantly changing, its protection is not 100%. It has also been observed that the vaccines produced this year are compatible with the H3N2 strain observed in Australia, but are less effective and cause a more severe flu picture.
