Noro viruses are distributed worldwide and are also one of the most common pathogens of classical gastrointestinal influenza in Germany. Although infections occur throughout the year, they reach a maximum during the winter months. More recently, cases of gastrointestinal influenza, in which Noro viruses are diagnosed as causing disease, are becoming more common. The Robert Koch Institute expects a massive number of cases of infection by the Noro virus this winter.
Course and severity
Infection with Noro viruses leads to typical symptoms within one to two days (incubation period). Indicators are:
- Sudden onset, violent vomiting
- Strong nausea
- Cramps and diarrhea
The infection is usually over after 12 to 60 hours, fever occurs only in rare cases. Diseases with the Noro virus are mostly mild, deaths due to infection are very low. Nevertheless, vomiting and diarrhea can lead to severe disease progression due to fluid loss, especially in elderly or sick people. Especially older people, who often do not drink enough, can literally "burn out" through the loss of fluid if they do not seek medical help. Therefore, it is important during the acute disease phase that the fluid loss is sufficiently replaced.
High infection rate of Noro virus
The Noro virus, also known as Norwalk, is transmitted via feces and vomit. In rare cases, it may also be transmitted by contaminated food or drinking water. The viruses are extremely environmentally stable and highly infectious - so already 10 to 100 virus particles are enough to trigger a disease. The high rate of infection - the so-called attack rate - is also due to the high concentration of virus in the stool and vomit of patients as well as the short-lived immunity to explain.
Danger for hospitals, old people's homes etc.
Infections with Noro viruses are more common in community settings such as hospitals, nursing homes, and childcare facilities. The high infection rates pose a particular danger for the staff and thus for the maintenance of everyday life in such houses. For this reason, a more stringent hygiene (eg protective gowns, mouth and nose protection and gloves, proper treatment of soiled areas and laundry ) necessary.
Infections with Noro viruses are among the four most notifiable infectious gastroenteritis in Germany - after infections by Salmonella, Campylobacter and Rotaviruses.