BRIAN DEER: MATTHEW AND THE BURGER BUG Page 2

Matthew's stool test was carried out in the Lancaster infirmary's microbiology lab, on the third floor of the pathology building, a few steps from ward 34. Last year, it processed 70,000 patient specimens, with the same equipment and procedures that are used throughout most of the United Kingdom. Under the direction of Dr David Telford, a bearded 49-year-old consultant, there is a chief technician, two seniors, eight technicians and two assistants, who work around a rack of pale green benches, "plating up" and testing for bugs.

All specimens are routinely checked for salmonella and campylobacter, but most are not screened for E-coli. Despite the explosion in the number of infections, there are still thought to be too few to justify the time and money. But where the sample is bloody, a three-day procedure is employed to additionally search for this bug. The material is incubated overnight in a yellow "broth", then scratched onto pink-jelly-coated dishes and left again until next day. If colonies of suspect bacteria have grown, some are studied on a slide with chemicals. Then more are incubated on a plastic strip, and the following morning the results are computed.

Matthew's sample was received on day 4 of his illness and found positive on day 7. But again there would be questions about the delay this caused in reaching a diagnosis of his condition. State-of-the-art methods used at a few centres around Britain could have slashed his wait by two thirds. "If we got a specimen at four or five o'clock this afternoon," explains Dr Peter Chapman of the public health laboratory in Sheffield, which uses these techniques, "we would be able to give you a 99.9% certainty result that it was E-coli O157 by 9.30am tomorrow."

Why Matthew never got such service was, like the decisions to treat him as a non-emergency case, purely a question of priorities. Chapman uses more advanced and expensive tests, has specially-trained technicians and, since investigating an outbreak at a Sheffield old people's home in 1983, has done world-class research on the organism. In contrast, the Royal Lancaster Infirmary does not have the time, and Telford's main interest is campylobacter. Far from his staff being seasoned in O157, moreover, until last September they isolated the bug on fewer than one occasion a year.

That, however, was until last September, which saw more reports of E-coli infections in Britain than in any other month on record. Another of the organism's unsolved mysteries is that there is a distinct annual season for human infections, which begins in May and peaks in the autumn - and which follows a kind of "blossoming" of the bacteria in cattle, which can be monitored several months ahead. As at hospital labs throughout the UK, the Royal Lancaster Infirmary's microbiologists' experience with the bug rapidly and frighteningly grew.

The most startling aspect was that Matthew's case was by no means one-off, even in his neighbourhood. Four days before his illness began, a Morecambe girl, aged 14 months, went down with diarrhoea and vomiting caused by O157. Forty-eight hours after her, a local 11-year-old boy got the same. On the day before Matthew's symptoms started, it was a 6-year-old girl, also in the seaside town. And then on day 8 of Matthew's illness (the morning after his test results), Rachael was horrified to discover that Tom, his brother, also had bloody diarrhoea. In the following weeks there would be three more children, making eight, within three miles of Torrisholme.

The cases had many of the hallmarks of the outbreak in Scotland, but it was not until the fifth was confirmed that local doctors were warned to be vigilant. "We have a small cluster of E-coli O157 infection in Morecambe," Telford faxed to 65 GPs on day 10 of Matthew's illness. "We are notifying practitioners in the area so they can be aware of this when they see children with diarrhoea and so that they can have a lower threshold for taking stool cultures and for considering hospital referral."

Rachael knew nothing of these other cases. Nor did the alert help Matthew. Despite the severe risk of complications, which can be expected in up to one fifth of cases involving children and old people, doctors decided not to admit any of those affected to hospital. Although antibiotics have no effect on the new E-coli, blood tests and close monitoring can help guard against possible problems like kidney failure. Yet these cost money or require scarce beds, so the advice was to stay at home.

Rachael was now coping with two sick children and, in the midst of this turmoil, an environmental health officer knocked on her front door. His name was Martin Brownjohn, a tall man, aged 42, who wore a dark suit and carried a black briefcase, from which he produced a thick questionnaire. He inspected her kitchen, looked in her fridge and asked her a string of questions. Where do you shop? What kind of foods have you bought? Have you been to restaurants or the chip shop lately? What kind of milk do you get? Have you been in the country, on farmland perhaps? Has your child been near any animals?

It was detective work, which he added to what he learnt from the other cases in what was now being called the "Morecambe cluster". Although the natural home of the new E-coli is cattle, it has been found in lamb, poultry, fruit juice, cider, lettuces, mayonnaise, milk, eggs and many other foodstuffs, which may be cross-contaminated in processing plants, shops, restaurants and kitchens. Some infections are directly from animals, especially at open farms. It has been found in water supplies and paddling pools. And up to one in six reports are thought to be like Matthew's brother's case: spread from person to person. By comparing the responses from each of the children's families, Brownjohn hoped to spot a common source.

The organism's incubation period is between one and eight days, so Rachael told him about the visits to McDonald's and the ice cream parlour, which also sold hot food. She expected that he would check these premises, but again the priorities question kicked in, and neither received a visit. Although ground beef is so often implicated that O157 has been dubbed the "burger bug", there was felt to be no advantage in spending time and public money on inspecting the restaurants. It was nearly two weeks now since Matthew had been to either. It was felt that the moment had passed.

Just as importantly, none of the other families had mentioned them as possible culprits. The 14-month-old girl, it was noted from the questionnaires, had eaten Asda ham and had recently been on holiday abroad. The boy aged 11, plus Matthew and Tom had eaten Asda ham and drunk Thornburrow milk. The six-year-old girl had drunk Thornburrow milk and eaten sausage from a take-away. A two-year-old boy had possibly drunk the same milk. And another, aged 13, worked on a farm at weekends. One child had nothing that seemed to stand out as a strong candidate for the cause.

The ham, mentioned in four of the eight cases, and the milk named in four or, possibly, five, seemed perhaps to point to something, but they were treated by investigators with caution. These were mass-market products which you would expect to be cited by any group of families questioned. "It is dangerous to jump to conclusions," says Steve Mann, manager of Lancaster's environmental health department, whose offices overlook Morecambe Bay. "We thought about the possibility of a low-level contamination of a nationally-distributed product, but the investigation was basically getting nowhere."

Rachael nagged Brownjohn, who called to see her again, but soon her insistence that the cause must be found was superseded by her other concerns. On day 10 of Matthew's illness (when Telford faxed the warning to family doctors), the toxins attacking Matthew's insides were making him so sick, with pain, diarrhoea and vomiting, that she called her GP, who came straight away and at last had the child admitted as an emergency to the Royal Lancaster Infirmary.

"I can't cope any more," she told him. "I've run out of bedclothes and everything."

"I agree," the doctor said, writing his referral letter. "I think it has gone on too long."

When they arrived at the hospital, Rachael got the feeling that opinions about the situation had changed there also. This time Matthew was rushed into an isolation room and a nurse arrived almost immediately and, for the first time, took a blood sample. It went straight to haematology and the results came back while Rachael waited by his bed. The analysis showed that he was suffering from anaemia, with red cells bursting and fragmenting. It showed that his platelets - clotting cells - were low, and that his creatinine and urea - waste products - were much higher than they ought to be. The diagnosis was haemolytic uraemic syndrome, a complication of E-coli poisoning. It is the biggest single cause of kidney failure in childhood. Matthew was gravely ill.

He needed dialysis. He needed it right away. But such is the priority for paediatric renal units that Lancaster does not have one. There are 13 children's kidney centres in the UK. A junior doctor hit the phones. Manchester was full. So a place was booked at Alder Hey, in the north-eastern suburbs of Liverpool. Stuart was called. Rachael's sister came for Tom. And Matthew was wheeled out and into the back of a waiting ambulance for the 50-mile journey south.

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This report is copyright, Brian Deer. Responses, information and other feedback concerning this resource on e-coli o157 food poisoning are appreciated - via the briandeer.com homepage.