Introduction
The Norovirus is the most common trigger of viral diarrhea with vomiting (gastroenteritis). It is characterized by a particularly high degree of contagiousness (risk of infection): Even the transmission of only a few dozen pathogens from one infected person to another is sufficient for an infection. In many other viral diseases, higher quantities of virus particles are often required for the disease to break out. This means that norovirus diseases often spread rapidly within a few days. Particularly in public institutions with close human contact, such as retirement homes or kindergartens, outbreaks can occur in this way, affecting a large proportion of the people accommodated and employed there.
How is the Norovirus transmitted from person to person?
Many viruses can only be transmitted from person to person through direct contact. For example, sexual contact is a prerequisite for the transmission of the HI virus that causes AIDS, and for the transmission of herpes simplex viruses, the two people concerned must be very fond of each other. The Norovirus, on the other hand, can also be transmitted indirectly from person to person.
Apart from the fact that the transmission of only a few dozen virus particles is sufficient for an infection, the indirect transmission possibility is the second major reason for the repeated waves of the norovirus. The virus is excreted by infected persons via stool or vomit. Virus particles can then be inhaled by other people who then fall ill.
In addition, there is also a risk of infection by touching objects to which virus particles adhere (e.g. door handles, toilets, keyboards) and subsequent contact of the contaminated hands with the mouth. And finally, the virus can also be absorbed through the consumption of food that has previously come into contact with infected persons. It is important: Infected persons are not only contagious during the symptoms, i.e. during diarrhea with vomiting! Shortly before the onset of the symptoms and especially up to two weeks after the end of the disease, they can excrete virus particles via the stool, which in turn can trigger the disease in other people.
