Noroviruses are highly contagious and are transmitted via the faeces and vomit of infected people, either through contact with infected people or objects touched by them or via food and water. The incubation period is about one to three days.
The main symptoms of infection with norovirus are diarrhoea, stomach pain and vomiting. Infection can occur at all ages, with young children and the elderly particularly at risk from dehydration after infection.
Currently there are no drugs that can control or prevent infection by norovirus. Outbreaks are best controlled by strict hygiene measures to prevent further spread of the virus.

More information on norovirus: ECDC & CDC