Is there a reliable way to make salad vegetables safe without cooking them?

Karen - A good question. I mean, the really important thing about the EHEC is that it requires very, very few bacteria. If your food is contaminated then you basically have to bleach it to get rid of them and make it really safe. We really don't want to do that because the toxins and the bleach would be harmful in themselves. Washing as thoroughly as possible as well, and hoping I suppose. I mean, that's a really difficult question because as you say, you can't cook salad vegetables, and you don't necessarily not want to eat them because of the chances of them being contaminated. As long as they're not from a source where this contamination has been found the risk is actually quite low. I don't know the answer to that question.

Chris - Because when people make motorway service station sandwiches and things like that, the salad in these pre-prepared sandwiches has already been washed in a weak solution of bleach, hasn't it? And I guess the problem with these bugs is if they get into small imperfections in the surfaces of the vegetable, so little nooks and crannies there, the bugs can lurk. The infectious dose is so low, it's just a handful of organisms at most that actually cause disease, and as you peel it, boil it, or leave it, then you're pretty likely to get it.

Karen - I mean, that's exactly right. Yeah, I mean, even washing them in a weak bleach as you say, they'll be lurking. If they're there, they can lurk right down in bits that will not be penetrated by the bleach and you still eat them. Yes, 6 to 10 will actually cause an infection of these particular bacteria.