As the Fonterra botulism story continues to rage in the media, here are a few links that people might find useful.
Fonterra Managing Director Gary Romano talking on Radio NZ Morning Report this morning – he confirms its the bacterium they have identified in the whey powder, not the toxin.
I talked about the story with Jim Mora and his panel on Radio NZ this afternoon.
Here is a report from 2008 written by Graham Fletcher and colleagues at Plant and Food in which they describe their research looking for C. botulinum in water samples from around NZ. They found 1 of their 501 samples tested positive by molecular tests for the presence of toxin type A which can cause disease in humans. They suggested testing soils to see how prevalent C. botulinum is here.
Lindstrm and colleagues have written quite a nice review about botulism and dairy products, with a table describing outbreaks (1). It was published in 2010 in the journal Critical Reviews in Food Science and Nutrition which my university does have access to so I could read it. The outbreaks listed go back to 1912 and have been mainly due to cheeses. They list one case due to contaminated commercial infant formula which happened in the UK in 2001 (type I/toxin B) – the child survived. Here is the paper describing that case in more detail (2). The authors found C. botulinum type B in an opened and unopened container of infant formula. Here are the important paragraphs (my emphasis):
“The infant formula powder consumed by the patient was made in a batch of 122 388 cans in October 1998, which was recalled by the manufacturer in August 2001, and was towards the end of its shelf life in October/November 2001.”
“From the estimate of the numbers of organisms in the unopened can and assuming a random distributed of C. botulinum in the batch, a 900 g can would on average have 13 C. botulinum spores and the probability that a tin had no organisms is very small (< 1 in 100 000). If an infant’s average daily consumption of milk powder is 130 g, then the probability of exposure to one or more C. botulinum spores is approximately 0.85 per day (this is calculated using the Poisson distribution and assuming that the tins tested represent a random selection of the batch), and if only this single case resulted from this level of contamination then the attack rate is 1 per 728 209 exposures to the bacterium.”
If we knew what level of contamination was in Fonterra’s whey powder, we should be able to use this information to estimate how likely it is that the cans of recalled Karicare are contaminated and hence the likely level of risk to babies.
1. (Miia Lindstrm, Jan Myllykoski , Seppo Sivel & Hannu Korkeala (2010) Clostridium botulinum in Cattle and Dairy Products, Critical Reviews in Food Science and Nutrition, 50:4, 281-304, DOI: 10.1080/10408390802544405)
2. Brett, M. M., McLauchlin, J., Harris, A., O’Brien, S., Black, N., Forsyth, R. J.,Roderts, D., and Bolton, F. J. (2005). A case of infant botulism with a possible link to infant formula milk powder:evidence for the presence of more than one strain of Clostridium botulinum in clinical specimens and food. J. Med. Microbiol. 54:769–776.