Influenza is an infection caused by Influenza viruses A or B. In common use, „flu“ is often used for influenza infects, these are several infects caused by viruses that are much less harmful than the „real influenza“. Influenza viruses and the diseases caused by them exist throughout the world – influenza-c type viruses are in contrast to the other two types fairly uncommon.

Disease transfer

The virus is transferred either by airborne infection, i.e. direct inhalation of respiratory droplets of infected persons or by contact- or smear-infection with the viruses on body- or object surfaces. The highly infectious viruses access over nasal mucosa (i.e. eyes, mouth or nose) into the body. A danger of infection also exists by contaminated faeces of infected animals or vectors or mechanical via hair, skin or feathers.

Aetiology / Symptoms

Symptoms will show after an incubation time from some hours up to several days. Having an incubation time of several days, the infected person can transmit the virus to other persons. In general, the indications of the disease are unspecific. Characteristic is the often sudden burst of the disease. The most important symptoms are: a distinctive feeling being disease-ridden in the whole body, high fever up to 40° C, headache and drowsiness, watering eyes, dry coughing and throat, swollen nasal mucosa, common cold and pain in the limbs.

Complications

The dangerous element in having an influenza is often not the virus causing the disease, but the following bacterial superinfection. As the organism is already enfeebled by combating the influenza viruses, there is no problem for bacteria to infiltrate the body and cause further diseases. In the most severe form an influenza infection may leed to primary pneumonia or even causes death within hours, if the person is already infected or has a low immunity shield. Younger and older persons face a higher risk here. Further complications can be brain- (encephalitis) or heart muscle inflammation (myocarditidis). In the meantime medicines such as Tamiflu® (Roche) and Relenza® (GSK) are in use for the treatment of an influenza infection, they strongly reduce the virulence and the symptoms of the disease but only if they are used in the first 24 to 30 hours after the first appearance of symptoms. Especially for high risk groups, it is useful having a home test within reach to be able to make a diagnosis at the appearance of the first symptoms. Having a positive test result, you can immediately get medical aid and a treatment can be started.