Monday, June 6, 2011
ANOTHER U-TURN IN THE E.COLI OUTBREAK INVESTIGATION?
So the culprit vegetable for the huge toxic E.coli outbreak was declared to be (Spanish, imported) cucumbers. And then it wasn't cucumbers. Next it was (German-Saxony, organic) bean sprouts. And now doubt is being cast too on this being the criminal food. Talk of a mess! And talk of an embarrassing situation for German officials. And, a very frustrating situation for all the people living or visiting Northern Germany who are trying to not starve to death or ruin their health, but not knowing what to eat.
But I am a little sympathetic, because of the pressures and challenges involved in solving this mystery. If you have "been in the business" - as I have (among other things, having done bacteriology in public health laboratories), you tend to be more aware of the barriers and pitfalls. For one thing, particularly in the case of food, sufficient numbers of bacteria rarely turn up in every single sample. So you may get some negatives as well as positives. In this case, the news reports 23 out of 40 samples from the farm had turned out negative so far. There are still 17 to go. Let's see...
But there is also the chance - although less likely - that the bacteria entered at a later point. There are still other possibilities as well. I don't have the details on when the sprout samples were taken, but conceivably, it might be possible that the contamination was temporary, in that it only affected sprout crops at a certain period of time (around end of April to early May). This could have been a rainy period, with more runoff from fields where cattle were grazing. Or, perhaps wild animals (which can also carry such bacteria) were running around then, and are now gone. Sprouts do spoil rather quickly, so there may have been none of the original samples left on which to do tests.
Investigating the cause of a food outbreak is always a challenge, particularly with perishable produce or perishable legumes, unless you just happen to get lucky (for instance, finding the contaminated food sitting in the refrigerator of someone who has become ill). But, admittedly, this is one for the history books.
To your good health,