Influenza is an acute viral infection of the upper respiratory tract caused by influenza viruses. The annual seasonal increases in influenza cases during the autumn and winter are caused by influenza A and B viruses. Influenza is transmitted through droplets when sneezing and coughing, as well as through close contact.
Influenza symptoms appear suddenly (sometimes within just a few hours) and may last from several days to several weeks. The most common symptoms are:
- headache
- high fever or low-grade fever
- chills
- muscle aches and general weakness
- cough and sore throat
- difficulty breathing.
The illness usually resolves on its own after 3–7 days, but cough, fatigue and feeling unwell may persist for up to approximately 2 weeks. The most common complications are:
- pneumonia caused by the influenza virus or secondary bacterial pneumonia
- bronchitis and bronchiolitis
- middle-ear infection (especially in children)
- inflammation of the heart muscle and pericardium.
Those particularly at risk of complications include:
- people over 65
- people in so-called high-risk groups, regardless of age
- people with asthma and other chronic respiratory conditions
- people with cardiovascular and kidney diseases, weakened immunity, etc. (e.g. transplant recipients and people living with HIV).
In Poland, the period of increased influenza activity lasts from October to April of the following year, with the peak occurring between January and March.
To protect yourself from influenza, follow these rules:
- get yourself and your loved ones vaccinated against influenza, including during the influenza season
- follow respiratory hygiene rules – when coughing or sneezing, cover your nose and mouth with a disposable tissue
- wash your hands with soap and water as often as possible
- when away from home and travelling, always carry hand sanitising gel or liquid, or a supply of disposable tissues soaked in an alcohol solution, as travel conditions rarely allow you to wash your hands frequently
- if you have just run out of disposable tissues or gel, sneeze and cough into the crook of your elbow – your hands will not become contaminated with the virus and you will not transmit it to others
- in public places and on public transport, avoid unnecessarily touching surfaces and fixtures
- avoid mass gatherings and close face-to-face contact with other people
- make sure that your child also follows the above recommendations
- if symptoms such as fever, headache, muscle and joint pain, cough, sore throat or shortness of breath occur, contact a doctor.
If influenza is suspected or diagnosed, do not go to work; stay at home until your symptoms have subsided.