Around thirty cases of the disease have been reported in the past week by laboratories around the country. This is more than at the same point in 2003, 2004 or 2005, according to the Swedish Institute for Infectious Disease Control (SMI).
Winter vomiting disease is caused by an infection of the Small Round Structured Virus, also known as Norwalk-like virus. Its symptoms include projectile vomiting, diarrhoea and fever, which usually last about 48 hours.
The disease is usually spread person-to-person by the faecal-oral route, and its spread is best prevented by good hygiene when using the bathroom. It can occur at any time of year, but is most common during the winter. The infection is unpleasant, but rarely dangerous.