A grandfather rang our surgery concerned about his nine-year-old grand-daughter, who had been unwell for two days with vomiting and diarrhoea. He'd heard the news about the recent outbreak of E. Coli at a Surrey farm and felt she should be seen by her GP.
It isn't unusual for children to attend their general practice with gastric infections. Nor is it uncommon for family members to express concern about rare, but serious, infections that often hit the headlines, most notably meningitis, but in this instance E. Coli 0157.
E. COLI 0157
So what is E. Coli 0157 and why should we worry about it? Escherichia coli (E. Coli) is, in fact, a commonly occurring bacteria found in the intestines of warm-blooded animals, including humans, and excreted in faeces.
Several strains exist, many of which are harmless. Some strains, however, can cause illnesses, including urinary tract infections, diarrhoea and blood poisoning, known as septicaemia.
Some of the strains that cause illness in people are known as vero cytotoxin-producing E. Coli, referred to as VTEC, and 0157 is the strain of E. Coli that is considered the most important illness-causing VTEC in the UK.
This particular strain is found in many animals, including cows and sheep. Humans may be infected by direct contact with these animals or from farms, contaminated water or food products.
Historically, outbreaks have also been linked to cheese, salami, apple juice, pies and even raw vegetables.
INFECTION AND SYMPTOMS
Humans may pass VTEC 0157 from one to another, particularly with poor handwashing practices. Worryingly, it takes as little as 100 bacteria to cause infection.
Once exposed, the incubation period for VTEC 0157 ranges between two and 14 days, although in most cases, it is around four days.
The diarrhoea caused by VTEC 0157 may be mild although, in certain cases, significant inflammation of the bowel may occur, with bloody diarrhoea and severe abdominal cramps. This is known as haemorrhagic colitis.
Patients with haemorrhagic colitis may also suffer from vomiting but, perhaps unexpectedly, they tend not to have a fever. The diarrhoea tends to clear within a fortnight.
SERIOUS CONDITIONS
The most serious of conditions caused by the 0157 strain are haemolytic ureamic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). While both of these conditions are rare, they are highly dangerous, and outbreaks often make the national news. Children are particularly at risk of developing HUS. July to October tends to see the highest rates of disease and this year is no exception.
Up to 7 per cent of those who have VTEC 0157-related diarrhoea go on to develop HUS.
Haemolysis refers to the breakdown of red blood cells and subsequent anaemia, whereas uraemia refers to kidney failure. Irritability, drowsiness and coma may also be a feature of HUS. Ten per cent of those who develop HUS will die of the disease.
TTP tends to occur more in adults. Thrombotic implies blood that is more likely to clot and block blood vessels, and thrombocytopenic relates to lower platelets than normal. Thrombocytopenia may also be a feature of HUS. Purpura describes a rash that doesn't blanche on pressure.
CHILDREN
It is important to remember that most children with diarrhoea and vomiting do not have VTEC 0157. Nevertheless, E. Coli should always be borne in mind, particularly in those who experience severe abdominal pain and bloody diarrhoea, especially in the absence of fever.
In these cases, or when the child looks unwell, it is crucial they are referred to a doctor for assessment. Patients with VTEC 0157 will be admitted to hospital for observation and to make sure they don't become dehydrated.
NURSERIES
Affected children should not be allowed back to their school or nursery until they have recovered and once they have two stool samples test negative for VTEC 0157.
Similarly, affected health workers or staff working in schools and nurseries should only be allowed back once they arae well, with two clear stool samples.
If the outbreak occurs in a school or nursery environment, the establishment should be closed and cleansed.
MESSAGES
The messages here are simple ones:
- practise high standards of food hygiene
- wash your hands thoroughly and ensure children do the same
- always seek medical advice if you are concerned about the health of a child.
REFERENCE
Shedding light on E. coli O157 - What you need to know, www.scotland.gov.uk/Publications/2005/03/20839/54389
Dr Raj Thakkar BSc(Hons) MBBS MRCGP MRCP(UK) is a full-time GP in Buckinghamshire
