Viruses that trigger diarrhoea and vomiting are particularly active during the cold season. Norovirus is the most frequent causing agent of gastrointestinal diseases.
Noroviruses at a glance
Norovirus gastroenteritis primarily occurs in the winter months. Characteristic symptoms are diarrhoea, sickness and explosive vomiting, heralded by lassitude, headache and sickness, and involve loss of water and electrolytes.
High risk of infection
The usual transmission path is smear infection, for example, via hand contact with contaminated objects or surfaces. Transmission via contaminated food and drinks or via droplets that might develop during vomiting is also possible.
Noroviruses spread extremely fast and their infectiousness is very high: only 10 to 100 virus particles are enough to elicit an infection. The time between being infected and the beginning of symptoms is between 6 and 50 hours.
Course of the disease
Gastroenteritis triggered by norovirus rarely involves complications in otherwise healthy people. As soon as infected with noroviruses, the acute disease lasts for an average of 24 hours. The symptoms of the infection normally disappear within 48 hours. However, the loss of minerals caused by the disease can be life threatening to elderly people and people with general weakness.
Risk of infection – even after recovery
The risk of infection is highest during acute disease. But be careful: also recovered people may excrete the virus for 1 to 2 weeks (in rare cases even significantly longer). Noroviruses can remain infectious on surfaces up to 7 days. There is no vaccine or specific therapy.
Robert Koch-Institut (2008) Noroviren (Noroviruses). RKI-Ratgeber für Ärzte, vom 26.07.2008. - www.rki.de (accessed on 22 September 2014), (in German).
Robert Koch-Institut (2013): Infektionsepidemiologisches Jahrbuch meldepflichtiger Krankheiten für 2013 (2013 Yearbook of Infectious Disease Epidemiology) - www.rki.de (accessed on 22 September 2014), (in German).