Infection and incubation period
You are considered to be contagious as soon as you are infected with the virus and carry it inside you. This means that those affected who do not yet show symptoms can still be contagious for other people. The reason for this is that the virus is still in a state in which it multiplies within the body.
This period is called the incubation period. The affected persons do not know at this stage, of course, that they are considered contagious. The highest risk of infection is in the acute phase of the disease, when the virus load is at its highest.
But even after the symptoms have subsided one is still contagious. The pathogens are excreted with the stool and could still be detected two to three weeks after the acute phase. However, the risk is constantly decreasing as the immune system kills the viruses and therefore the viral load in the stool decreases from day to day.
In medicine, the incubation period is the time between infection by a virus or pathogen and the appearance of the first symptoms. By incubation (lat. incubare = “to incubate”) is understood the rapid multiplication of the pathogens until they have multiplied so much that they damage the body and cause corresponding symptoms.
The typical gastrointestinal viruses that cause gastrointestinal influenza are the norovirus and the rotavirus. These have an incubation period of approximately four to 50 hours. The incubation period depends on the patient’s general state of health (especially the functioning of the immune system), as well as on the so-called infectious dose.
It describes the minimum number of virus particles required to trigger an infection. For the norovirus, ten to 100 viruses are sufficient. The problem with the incubation period is that those affected are already infectious without knowing it themselves.
Causes of a gastrointestinal virus
- Noro virus
- Rota virus
- Contaminated food
- Lack of hygiene
There are two gastrointestinal viruses that play a decisive role as the cause of a gastrointestinal infection. These include the Noro virus and the Rota virus. The Noro virus is an unenveloped RNA virus, just like the Rota virus.
Since both viruses are unenveloped, it is particularly difficult to remove the virus using disinfectants. Especially in the winter months, the gastrointestinal viruses cause an outbreak of the disease. Especially the Noro virus is very feared because it is very contagious and can lead to severe diarrhea.
The transmission of the viruses takes place fecal-orally. This means that a patient who forgets to wash his hands after going to the toilet (i.e. who indirectly comes into contact with his faeces) carries the virus on his hands and then passes it on to the second patient when he shakes hands with him. If this patient touches his mouth with his fingers, he takes the virus orally.
Just a few virus particles are enough to trigger a gastro-enteritis in the next patient.However, it is also possible to ingest the gastrointestinal viruses via contaminated food. Frozen strawberries or roast chicken can be the cause for the transmission of the gastrointestinal virus. Another cause is lack of hygiene.
In Germany, for example, a small boy caused a small epedemia by vomiting in the opera house because he was infected with the gastrointestinal virus. All other opera-goers who used the same toilet afterwards also fell ill with the Noro virus within a few hours. Usually the symptoms disappear again after about 2 days, but it is possible that the virus persists longer in the intestine and then leads to dangerous water loss (dehydration).
In general, there are other different viruses that can be regarded as gastrointestinal viruses. These include, for example, the enteroviruses, astroviruses or the adenoviruses. However, since these rarely lead to a gastrointestinal infection, the two main players, the Noro virus and the Rota virus, are discussed here.
