Outbreaks of gastroenteritis caused by noroviruses have become an increasing problem for institutions in the health-care system over the past years. Staff members are also afflicted by the outbreaks of infection due to the highly contagious nature of noroviruses and this can lead to bottlenecks in health-care management and to economic losses. An acute gastroenteritis due to norovirus usually begins with severe nausea, heavy often projectile vomiting and a pronounced feeling of unwellness. In addition, there can be diarrhoea and abdominal cramps. The incubation time amounts to around one day. As a rule the disease is self-limiting and clears up after 2 to 3 days. However, the clinical pictures for one and the same type of pathogen can vary markedly from mild to severe illness. Since there is no way to treat the cause of a noroviral infection, prophylactic hygiene measures, especially of standard hygiene, are of particular importance. The necessary hygiene measures (especially hand hygiene) are aimed at interrupting the faecal-oral transmission pathway.