Causes of the gastro-enteritis
A stomach flu is an inflammation of the gastrointestinal mucosa (gastroenteritis) caused by viruses or, more rarely, bacteria. Although the name “flu” suggests an infection with the influenza A virus, the two diseases have nothing to do with each other. The gastrointestinal flu always has a viral or bacterial infestation as its cause.
In humans, the so-called Noro virus is particularly common as the cause of the gastro-intestinal flu. The viruses are usually transmitted faecal-orally, which is mainly due to a lack of hygiene. Faecal-oral means that if the first patient has been to the toilet and has not washed his hands after defecation, his hands are still contaminated with the virus.
As soon as he then shakes the hand of a second person and the latter then runs his finger briefly over his lips, this second person has the virus on his lips and thus quickly in his mouth (orally). Thus, a lack of hygiene can also be regarded as a further cause of gastro-enteritis. Influenza viruses belong to the group of orthomyxoviruses and are so-called RNA viruses because their genetic information is available as RNA (=ribonucleic acid).
An infection with influenza viruses of type A, B or C leads to influenza. Infection occurs by droplet infection, for example by coughing or sneezing of infected persons, whereby viruses reach the eyes through inhalation on the mucous membranes of the mouth, nose, throat or through the air. Tiny amounts of the viruses are enough to cause influenza, as influenza viruses are highly contagious.
But also smear infections, e.g.B. by touching objects previously touched by sick persons and subsequent touching of mouth, nose or eyes can lead to a flu infection. Flu viruses can remain contagious for some time under favorable conditions: At room temperature, they remain active as a so-called aerosol for up to one hour in the air of the room; on smooth surfaces that have come into contact with nasal secretions or exhaled air of infected persons, they remain active for up to 48 hours.
The incubation period (time from first contact with the virus until the illness) is between 18 and 72 hours and depends on the amount of virus inhaled. People who are ill with influenza excrete viruses themselves for at least two days, sometimes even up to five days, and can infect others with them.
