Influenza is sudden inflammation of the respiratory tract caused by the influenza virus (types A and B). Every year influenza viruses cause epidemics affecting 5-15% of the population. An epidemic is referred to as a pandemic when a greater than normal proportion of the population are affected and the disease is more severe than usual. The last pandemic occurred in the winter of 2009-2010 (H1N1 virus) and was called swine flue.

In Finland, the seasonal influenza epidemic usually starts around New Year and lasts for 2-3 months. Influenza is transmitted from one person to another through droplet transmission. Influenza spreads easily, especially in confined spaces such as in schools, garrisons and on public transport. The incubation period is usually 2-3 days.

Influenza typically starts with a high fever. Persons with influenza also experiences muscle pain, non-productive cough, chills, headache and feeling unwell. Children may also have gastrointestinal symptoms.

Influenza symptoms are usually more severe and last longer than a common cold. In persons who are otherwise healthy, influenza usually resolves spontaneously. Influenza symptoms are treated by resting, non-steroidal anti-inflammatory drugs (e.g. Burana) and/or paracetamol (e.g. Panadol). If the symptoms are exceptionally severe or persistent, a bacterial infection after influenza (pneumonia, sinusitis or middle ear infection) should be suspected. There are also antiviral medicines against influenza. These are given to patients with severe symptoms, pregnant women, risk groups and in certain special cases.

Influenza can be prevented through good hand hygiene and correct coughing technique. Persons with symptoms should stay at home. Vaccination against influenza is also effective. Seasonal influenza vaccines are free of charge for healthcare workers, pregnant women, persons over 65 years, children aged 6-35 months, conscripts, persons who, because of their illness or treatment, belong to a risk group (e.g. asthma, diabetes) and persons close to those exposed to serious influenza. Students belonging to risk groups can be vaccinated at the FSHS. If you are not entitled to vaccination free of charge, you can buy the vaccine at a pharmacy with a prescription from the FSHS.

This article was written by:
Minna Paavonsalo, GP
September 2014

Key words: Influenza