How to avoid food poisoning this summer

Ask the average man on the street (or doctor, for that matter) what causes food poisoning and they'll say meat. But in recent years, there have also been really nasty outbreaks of E. coli linked to salad leaves.

I regularly have to advise my patients with urine infections that they have an E. coli infection, which is responsible for 90% of cases of cystite. But there are numerous strains of E. coli, and some are far more dangerous than others. In fact, most of us have E. coli living harmlessly in our guts - although if it gets into your bladder it can cause inflammation and the painful burning of cystitis.

One of the nastiest varieties - and fortunately one of the least common - is the E. coli O157. It's a member of the VTEC family of E. coli - unlike other E. coli strains, these produce poisons (toxins) responsible for much of the damage. Some people infected suffer 'common or garden' gastro-entérite, with diarrhée, tummy cramps, fever and vomiting for a few days. But some get more severe inflammation, with bloody diarrhoea and occasionally profuse bleeding due to defective clotting, or kidney failure.

Of course, we've also had a heatwave this year. Add to that the start of the summer holidays, and picnics and barbecues are on all our minds. But the average doctor - or professional caterer - is more likely to be worrying about intoxication alimentaire than salivating over the sausages. Because without the right precautions, both treats can have all too unwelcome results.

The four Cs

The Food Standards Agency recommends the four Cs to cut the risk of food poisoning:

Cleaning

Wash hands with soap and water before touching food or smoking a cigarette, and after you go to the bathroom (obviously!), or touch pets or rubbish bins. If you have a tummy bug you should avoid preparing food for at least two days after your symptoms have settled. Remove all soil from salads and veg before you store it, and wash all fruit and veg that will be eaten raw thoroughly.

Cuisson

Cook chicken/sausages/burgers/seafood right through, so juice runs clear when a knife is inserted into the thickest part.

Refroidissement

Warm meat, and also rice dishes are perfect breeding grounds for germs. Keep food in the fridge or a cool box until the last minute. Return leftovers to the fridge as soon as possible (within a maximum of two hours); and keep your fridge at 1-5°C.

Contamination croisée

Raw meat is still the biggest culprit where food poisoning is concerned, so store raw meat in drip-proof containers, separate from cooked. Use separate knives and chopping boards for raw meat, cooked food and veg and never wash raw poultry before you cook it.

If you're anything like my patients, you're probably now wondering what the 'thoroughly' bit of 'wash thoroughly' actually means. You may not be surprised to hear that opinions vary. Some food hygiene specialists recommend soaking most veg for 15 minutes to ensure all soil particles are gone. Others apply that rule only to potatoes or other veg that grow completely underground. Instead, they advocate getting rid of outer lettuce leaves which harbour most soil, and washing the rest thoroughly under running water. Pre-washed bagged salad is an exception - it's usually safe to eat without extra washing.

I'm acutely conscious that yet again I get to be the killjoy, predicting doom and gloom even on the balmiest of days. But I'm not suggesting you avoid fruit and veg completely - the risks are far outweighed by the lifelong benefits to your health. I'm not even suggesting you avoid the barbecue - I just don't want to see you in my surgery as a result!