Twenty-eight cases of shigella flexneri, a type of dysentery which causes diarrhoea and stomach cramps, have been confirmed. Sainsbury's says the cause has yet to be confirmed but "statistical evidence" shows the outbreak was associated with fruit from the salad bar.
But should we really be surprised? The number of food-poisoning cases rose by 10 per cent last year to 105,552, and has risen every year for the past 15 years. While most food poisoning incidents take place in the home, food outlets are increasingly coming under the spotlight. At the moment there is no legal requirement for the person who is cooking your chips or concocting your creme brulee to have any training in food-handling skills. Food safety experts say that if the Government does not act, cases will continue to rise "inexorably".
Shigella flexneri, which surfaced in Haywards Heath, is thankfully rare - there were only 600 cases last year, according to the Public Health Laboratory Service.
The most common cause of food poisoning is campylobacter, found in raw meat and poultry, animal faeces and, occasionally, tap water. It causes abdominal pain and diarrhoea but is not as serious as other bacteria, such as salmonella (which has tripled since 1981), listeria, and E.coli which, in its O157 strain, can cause kidney failure and death.
This week, the inquiry into the world's worst outbreak of E.coli O157, in which 21 people died, accused the butcher at the centre of the case, of "deliberate deception". Sheriff Principal Graham Cox ruled that, had John Barr responded "fully and honestly" with officials investigating the November 1996 outbreak, then six lives might have been saved.
But even in less serious cases, there are still enough horror stories to put anyone off their grub. One survey last year found 12 different urine traces in a bowl of pub peanuts.
This month, Health Which? warned fast-food lovers they could be munching something nasty. Their survey found "unsatisfactory" levels of bacteria in a wide range of foods, with kebabs the main risk to health. One doner kebab contained Listeria monocytogenes which can cause septicaemia, meningitis and miscarriages, and Staphylococcus aureus which can cause severe vomiting and abdominal cramps.
"One of the problems is cross-contamination," says Tom Bell, training adviser for the Royal Environmental Health Institute of Scotland. "The classic example is a restaurant with cramped conditions where they prepare raw and cooked meats on the same worktop."
The other key issue is temperature control, according to Simon Williams, of the Chartered Institute for Environmental Health. "With something like a salad bar, by law the temperature must be under 8C, and then, for hot food, the temperature must be 63C. The danger zone is between those two temperatures, where bacteria will flourish.
"The other issue is ensuring people don't breathe on food - mainly the food-handling staff, but there are chains where they have self service for the customers. If you've got an infectious illness you really shouldn't be handling food, and food outlets should put glass units over the top."
But food experts warn that too many establishments are ignorant of basic food hygiene. "I've seen places where they've had raw meat dripping blood on to trifles underneath," said Mr Bell. "It's unbelievable."
"There has been a huge shift in recent decades towards eating out and yet there hasn't been enough pressure to improve the training of people who work there," added Tim Lang, professor of food policy at Thames Valley University. "As a result, food-poisoning cases have risen inexorably.
"The basic rules are being broken. Anyone can set up a food business and they merely have to register themselves under the Food Safety Act."
Mr Williams said: "At the moment there is no legal requirement for businesses to train their staff. In 1995 we thought the government was going to introduce it, but at the last minute they bottled out."
Professor Lang said: "We believe strongly that this is the next big change this government has to pick up and run with. People like me gave the last government a hard time because they just believed in the free market. But you can't have a free market of microbes."
BACTERIA THAT SPELL DANGER ON YOUR PLATE
Some nasty organisms that may lurk in your food...
Botulism: Rare, but has a mortality rate greater than 50 per cent. Found in under-processed foods. A single case can signal a national emergency. Symptoms include dry mouth, constipation and blurred vision. Death results from respiratory muscle paralysis. In 1989 there was a scare after a contaminated batch of hazelnut yoghurt was found.
Campylobacter: Most common cause of food poisoning. Found in raw or under-cooked meats, unpasteurised milk, occasionally in water and animal faeces. People have even become infected by drinking milk contaminated by birds pecking milk-bottle tops on the doorstep. Destroyed by proper cooking but it takes only a small number of bacteria to make you ill. Usually causes stomach cramps and fever, as well as the usual symptoms.
E.coli: Transmitted through under-cooked food, particularly beef, milk and vegetables. Can also be caught through contact with infected people or animals. In the most serious cases can lead to kidney failure and death. Most serious strain is O157 - the world's worst outbreak was in Scotland in 1996 when 21 died.
Hepatitis A: Person to person contact or through consumption of untreated water, contaminated shellfish, and foods eaten raw or washed in these waters. Young people may have no symptoms; older people may develop jaundice, abdominal pain, itching, fever and nausea.
Listeria: Mainly a danger to pregnant women or people with a poor defence to infection. Found mainly in soft-ripened or blue cheeses, pates or TV and microwave meals. Unlike many bacteria, it can survive freezing, sparking a variety of diseases, from a mild chill to meningitis in newborns.
Salmonella: One of the most common causes of food poisoning. Transmitted through cross-contamination of raw and cooked foods including meat and dairy products but most notoriously eggs. The bug is killed by adequate cooking. Usually illness lasts two or three days, but it can lead to septicaemia and severe illness, or even death.
Shigella: This bacteria causes bacillary dysentery. Transmitted through contaminated water or raw foods. Symptoms include abdominal colic, diarrhoea and fever. Duration of the illness can last from a few days to two weeks depending on the strain.
Staphylococcus aureus: Transmitted through contaminated meats, milk and custard. The bacteria is carried in the noses of 40 per cent of the population. In the right conditions it forms a toxin on food. Acute food poisoning takes place within an hour or two of being eaten. Can cause severe vomiting and cramps.