The winter vomiting bug, as the name suggests, is a condition that causes vomiting, as well as diarrhoea, headache and fever.
The virus that causes the condition is highly contagious and is responsible for significant outbreaks in institutional settings, such as hospitals, nursing homes, or confined environments such as cruise ships.
Contrary to the name, the vomiting bug can occur in summer as well as winter, although it is more common during the colder months.
Winter vomiting bug is usually caused by one of a family of viruses known as noroviruses. These viruses can be present in contaminated drinking water or foodstuffs such as shellfish, salads and fruits. Once a primary infection has occurred, the virus can be transmitted from person to person in the air or on surfaces.
Faecal matter contains significant quantities of virus and can cause the spread of the disease from toilet seats and toilet handles, for example.
The symptoms of the disease occur 12-24 hours after infection and they persist for about three days. They typically include sudden nausea and projectile vomiting, watery diarrhoea, fever, aching limbs and stomach cramps. A person remains contagious for up to two days after the symptoms have subsided.
Since the infection is caused by a virus, antibiotics are ineffective against the condition. Symptomatic treatments can be given to reduce the vomiting and diarrhoea and it is important to maintain hydration, particularly in very young or elderly patients.
Once a person has had winter vomiting bug, they have very limited immunity against future infection. However, since the virus family is quite large, future infections are likely to be caused by a different strain of the virus.