Considering the pandemia we are facing since the beginning of the year, we are much more informed about the flu. People who are not interested in molecular biology know what influenza means and even the newspapers are now telling us about the flu symptoms. This has a really good impact on public health and now that we are entering the flu season, it is called for. But are we sure that we are not misinformed? Did we fact-check about such an important issue? Now let’s take a look at seasonal influenza and get our facts straight before the flu season.

Flu is a viral illness which infects the respiratory system. The airborne respiratory virus is highly infectious. It is spread through coughing, sneezing, talking and also contacting contaminated surfaces and then touching the nose, eyes or mouth – very much like novel coronavirus, right? 

New flu vaccines are awaited every year because the viruses that cause flu can change their genetics periodically. Those viruses are called influenza. Influenza viruses which infect humans have 3 types: A, B, and C. Influenza C is usually not included in the seasonal influenza vaccine because it is believed that the cause of epidemics are influenza A and influenza B. If there is no contraindication, it is very important to be vaccinated annually.


Seasonal epidemic influenza activity usually begins in the late fall or early winter months. Other than the epidemic influenza, sporadic cases and institutional outbreaks are possible any time of the year. Even during the summer months occurence of the cases is possible.

Seasonal epidemic influenza cases usually appear first among 6-8 years old children. The attack rates in children are usually the highest. The lowest attack rates are among the elderly. On the contrary the rates of infection and serious disease are highest among the elderly, the very young and the people with chronic conditions who are prone to complications.


When we continue to investigate influenza from a pathogenetic aspect, the incubation period is typically 2 days. It can range from 1 to 4 days. For up to four days after this period the virus can be isolated from the nasopharynx of adults.

Influenza infection has a large spectrum from subclinical cases to fulminating viral pneumonia. Even though a typical uncomplicated case of influenza illness begins all of a sudden manifested by sore throat, headache, fever, chills, myalgias, anorexia and extreme fatigue, there are no physical examination findings specific for influenza. 


Other common manifestations include (usually nonproductive) cough, and a runny or stuffy nose. Photophobia, abdominal pain, and diarrhea are some of the less frequent manifestations. In most cases, recovery from the illness from influenza takes about a week. Cough and malaise may persist a little bit longer. 


Complications due to flu may also occur. For example secondary bacterial pneumonia may prolong the recovery process. FluAI is here to guide you in a healthy and faster recovery. It assists you with its machine learning technology and you can decide more confidently whether you need to go to the doctor or not. We are coloring the science!


  1. Harper, S., Klimov, A., Uyeki, T., & Fukuda, K. (2002). Influenza. Clinics in laboratory medicine, 22(4), 863–vi. https://doi.org/10.1016/s0272-2712(02)00022-7 
  2. Keilman L. J. (2019). Seasonal Influenza (Flu). The Nursing clinics of North America, 54(2), 227–243. https://doi.org/10.1016/j.cnur.2019.02.009 


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