Gastroenteritis commonly presents in primary care, acc-ounting for 20 per cent of GP consultations each year in infants and children under five years in the UK. The main symptoms are vomiting, diarrhoea, fever and abdominal cramps.
These usually start one to two days after infection with a virus or bacteria and can persist for up to 10 days.
Gastroenteritis is contagious and spreads through sharing food, water or eating utensils within families or nursery and school environments. Less commonly, food can be contaminated by the people who prepare it, especially if they do not wash their hands after going to the toilet.
The most common cause of acute diarrhoea is infection; 87 per cent of which is viral.
Rotavirus is the most common cause of severe diarrhoea among children. The highest rate of illness occurs in infants under two years. The disease is characterised by vomiting and watery diarrhoea.
The virus is stable in the environment so transmission can occur from contaminated work-surfaces and utensils. The disease has a winter seasonal pattern, with annual epidemics occurring from November to April.
Between 600,000 and one million people in the UK every year are infected with a norovirus. Symptoms of the disease are vomiting, diarrhoea, fever, myalgia and abdominal pains.
Norovirus is often responsible for outbreaks of diarrhoea in institutes such as hospitals and residential homes. It spreads quickly because it is infectious at a low dose.
Escherichia coli 0157
E coli 0157 is a mutant form of the E coli bacterium that lives in the intestines of some cattle and goats but is not naturally found in the intestines of man.
It produces toxins that are potentially fatal when ingested in very small amounts.
The symptoms of E coli 0157 infection can be very severe, but usually resolve within 5-10 days. Up to 70 per cent of patients have severe bloody diarrhoea and abdominal cramps, although sometimes the infection causes non-bloody diarrhoea or no symptoms.
Adult disease management
Adults and older children with no or mild dehydration can be managed at home.
Patients should be advised to consume at least two litres of fluid a day, and replace ongoing fluid losses with an additional 200ml for each loose stool. Oral rehydration solution is suitable, but may not offer any advantage over other liquids containing water.
Frail and elderly patients are at greater risk, so the threshold for admission should be lower. These patients should be advised to replace the fluid deficit more rapidly, with one to two litres over six to 12 hours, as well as replacing ongoing fluid losses.
Patients can continue with their usual diet but should avoid fatty foods and foods with a high sugar content as these may be poorly tolerated. They should continue oral rehydration until the diarrhoea resolves.
It is important to advise them on simple hygiene measures, such as hand-washing, to prevent the spread of infection.
Patients with gastroenteritis should be excluded from school or work for at least 48 hours after they are free from diarrhoea and/or vomiting.
Treatments other than loperamide are not recommended for gastroenteritis in adults. Antibiotics are rarely indicated; they should be reserved for patients with positive stool cultures, particularly if symptoms are severe or not settling.
Ciprofloxacin is occasionally required for those at high risk or who present with dysentery. The local consultant in Communicable Disease Control should be notified of cases of dysentery or suspected food poisoning.
In patients with an E coli 0157 infection, antidiarrhoeal agents such as loperamide or diphenoxylate with atropine should be avoided as they are likely to make the illness worse.
Treatment with some antibiotics can increase the risk of haemolytic-uraemic syndrome (HUS) in these patients. Children with HUS should be referred urgently for appropriate clinical management.
Management for children
Children should be assessed for dehydration (see box). In infants under 12 months, gastroenteritis should be treated with oral rehydration solutions. Breastfed babies should continue to be breast fed and normal diet given to weaned children, as much as possible.
Dr Warburton is a GP in Ironbridge, Shropshire.
| To examine a child for dehydration, assess: |