here is the link to the full article society.guardian.co.uk/health/story/0,,2090058,00.html which is mostly about alcohol but if you scroll down you can see the bit on listeria. I have cut and pasted the listeria bit below:
'Listeria
If you have the misfortune not to be pregnant, you might not know that the expectant mother is instructed by everyone, very forcefully, not to eat blue cheese or any cheese that hasn't been pasteurised, likewise unpasteurised milk and ice cream. Also you must not eat: rinded cheese, goat's cheese, pâté, terrines and rillettes, sushi, sashimi and artisan-smoked fish (as opposed to the industrial sort, which is smoked to death). This is besides the other fish injunctions, which tend to be about mercury - oh, and bagged salad.
Basically, if you can get it in a deli and it's costed per 100g, you probably aren't allowed to eat it. Most of these injunctions are about avoiding listeriosis, which is the disease proceeding from the listeria bacteria (apart from the mercury stuff, and "no liver" injunctions, which are about an excess of vitamin A).
Listeria has been my particular bugbear ever since a midwife - that is, a trained prenatal professional who, unless I develop complications, represents the highest medical authority I can expect to deal with throughout my pregnancy - told me that I could get listeriosis, thereby brain-damaging my foetus, without knowing about it. Now, listeriosis is an incredibly serious disease, with extremely serious symptoms, taken extremely seriously by epidemiologists nationwide. Get it without noticing it? If I got listeriosis, the national papers would know about it. It would be the third outbreak that has occurred in this country in the past 20 years. My beloved, C, said: "Well, she was just erring on the side of caution." This is a common line. But the distinction between "caution" and "misinformation" could not be more important - when it is blurred, as it so often is, the upshot is that pregnant women either become neurotic, or lose faith in the medical profession altogether.
Here are some other things that are wantonly untrue: pasteurisation, in fact, has nothing to do with a cheese's ability to harbour the listeria bacteria. The bacteria that characterise different cheeses are introduced after the pasteurisation process anyway. Listeria flourishes in moist environments, so parmesan is safe where camembert isn't, but even rinded and soft cheeses are safe once they have been cooked. But food hygiene is a much more important factor than moisture - raw fish does not come out of the sea carrying listeria, but contracts the bacteria from contact with dirty hands. Of the past two outbreaks of listeria in Britain, one was from butter and the other from lettuce (there have been other instances of product recalls, but no human contamination).
In fact the three worst recorded cases of list-eria since 1992 have all been in France, and were all from pork tongue in jelly, which nobody in their right mind would ever eat. Of the past 10 listeriosis outbreaks in America, only two were from cheese, and one of those was a Mexican homemade cheese. The notion that there are pregnant people out there whipping themselves into a frenzy of guilt because they have eaten some gorgonzola is just infuriating.
Jauniaux cites an interesting difference between Google hit rates and those on PubMed, a collected source of peer-reviewed papers in medical journals. "Listeria and pregnancy - Google, 190,000 hits; PubMed, 107 hits. Cheese and listeria - Google, 194,000 hits; PubMed, 169 hits. Sushi and pregnancy - Google, 628,000 hits; PubMed, 0 hits. Raw fish and listeria: Google, 123,000 hits; PubMed, 49 hits. You can see immediately," Jauniaux concludes, "the disproportion between the epidemiological evidence and the general public hysteria about the disease."
I wrote a potted rant about listeria hysteria some weeks ago in this paper, and readers emailed me accusing me of murdering people's foetuses with misinformation. Which is completely foolish. Jauniaux gave a lecture at the annual conference of bacteriologists two years ago, and no one in attendance had come across an outbreak of listeria in years. In England and Wales, the last figures for listeriosis were 2.7 cases per million (and that is among the entire population, not pregnant women). This risk is not negligible - tolerable risk is defined by the government as one in a million - but it is pretty small and, more importantly, the advice is misleading. In fact the potential danger comes from ready-to-eat foods: it could be anything that gives you listeria, it could be cheese or butter or lettuce or coleslaw; an ice-cream cake or a rice salad. In Spain, pregnant women are told not to eat any salad. All of this is overblown, and none of it is as effective as a simple food hygiene message, telling you to observe the basic rules that you would hold to if you were cooking for people you didn't want to poison: wash knives and boards, wash foodstuffs and so on.
And by the way: the most dangerous places to eat in Britain are hospitals and old people's homes, and that is before they have even had a go at treating you.'
Hope it puts your mind at rest a bit!
xx