VOL: 102, ISSUE: 23, PAGE NO: 21
What is it?
What is it?
- Norovirus refers to a group of viruses that represent the most common cause of gastroenteritis in the UK.
- It can cause severe diarrhoea and vomiting and is easily passed from person to person.
- It can be dangerous in older people or the very young due to the degree of dehydration.
- An estimated 600,000 to one million people are affected each year in the UK.
- The condition has also been known as winter vomiting disease and Norwalk virus (after Norwalk in Ohio, site of the first identified outbreak).
- It is transmitted from person to person by the oral-faecal route and spreads quickly in enclosed environments such as hospitals, schools and nursing homes.
- It can be contracted through the aerosols of projectile vomit.
- Environment is also a factor. It can be contracted from contaminated surfaces, for example in toilets.
- Contaminated food and drink, especially oysters and mussels, also present a risk.
- Incubation is usually 24-48 hours but can be only 12 hours. Symptoms usually last 12-60 hours and include:
- Projectile vomiting;
- Watery diarrhoea;
- Abdominal cramps;
- Seizures (occasionally);
- Recovery usually takes 1-2 days but diarrhoea may persist.
- There will be an absence of tenderness and no guarding on abdominal examination.
- Severe dehydration can necessitate hospital admission in infants and older people.
- In severe cases the dehydration caused by persistent diarrhoea and vomiting can cause electrolyte imbalance, hypotension and eventual collapse.
- Diagnosis is usually made by observation of the symptoms.
- Laboratory investigation of stool and vomit samples is usually only carried out to determine the cause of an outbreak and rule out other conditions such as salmonella or typhoid.
- There is no specific treatment except for letting the condition run its course.
- Drinking plenty of water is essential to guard against dehydration.
- Special care should be taken with infants and older people, as dehydration is more common in these age groups.
- Adults can use over-the-counter anti-diarrhoea medicine such as loperamide. This can help reduce the amount of diarrhoea. These medicines should never be given to children as the side-effects may be harmful.
- Outbreaks of norovirus are common in semi-closed public areas such as in hospitals, schools, nursing homes and cruise ships.
- Infection cannot be entirely prevented. However, there are measures that can be taken to minimise the impact of an outbreak:
- Frequent handwashing around people who are infected is crucial to prevent spread of the virus;
- Implementing basic hygiene and food handling measures;
- Disinfection of contaminated areas;
- Isolation of those infected for 48 hours after their symptoms have ceased.
- Control measures required in healthcare settings, such as closing wards to new admissions at the beginning of the outbreak, should be implemented within four days.