The reputation of NZ’s dairy giant Fonterra is taking another bashing with the announcement* of a voluntary recall of 8,700 bottles of cream** after tests indicated they may be contaminated with the food-poisoning bacterium Escherichia coli.
So what is E. coli, how did it get in the cream and should we all be panicking?
1. What is E. coli?
E. coli is an organism that naturally lives in the gastrointestinal tract of humans and many other animals, including cattle, and is shed in the faeces. There are many different types of E. coli which vary in the disease they cause and the doses needed for an infection. They range from relatively benign strains which require ingestion of large quantities to cause not much more than a short-lived upset tummy, to strains which produce nasty toxins and a small dose of which can cause kidney failure and death.
2. What strain of E. coli did Fonterra find?
Fonterra haven’t made this information public yet but they should have had time to run genetic tests to find out if the contaminating strain has any toxin genes. Given they are doing a voluntary recall and the announcement wasn’t strongly worded, I’d say it’s most likely a relatively benign strain they have found.
2. How was the cream contaminated?
The cream could have become contaminated anywhere from the cow to the shelf. Cows carry E. coli in their gastrointestinal tract, but it can also be present on their udders, where it can cause an infection known as mastitis. This is where the udder becomes inflamed and can result in changes in milk quality. Cows can also be asymptomatic, where the bacteria are present but do not cause mastitis.
Milk products are pasteurised to kill any bacteria that may have come from the cow or elsewhere in the process so it may be this that has failed with these particular batches of cream.
3. Why has the cream been recalled?
If the contamination had been of a product that required cooking, then it would be less necessary to do a recall. This is because the cooking would likely kill the bacteria. But cream is a product that tends to be consumed whipped and on a pavlova, hence the recall.
4. I’ve already eaten some of the affected cream. Should I be worried?
As its a voluntary recall, I’d say not. Symptoms normally appear within 1-3 days after infection so if you ate from a contaminated batch more than 3 days ago, then you have nothing to worry about.
* It’s E. coli Fonterra media peeps, not E.Coli.
**The bottles are 300ml and 500ml bottles of Anchor and Pams fresh cream with a best before date of 21 January 2014, with batch numbers 1400684206, 1400684207, 1400684208 and 1400684209, distributed from Northland to Turangi, and Gisborne.
UPDATE 15/01/2014: Reports are now saying that the contamination is thought to have happened post-pasteurisation.