Wild meat and botulism - update.

As I suggested in the original post, the tests on food and other samples have now shown that the poisoning of the family in New Zealand, apparently caused by Clostridium botulinum, was not caused by botulin toxin. However, no other explanation for the families symptoms is forthcoming. Conspiracy theorists are suggesting the boar had consumed 1080 poison (used for possum control) but there is no evidence for this. Many other toxins could be involved - fungal or plant toxins, or even toxins in spices brought from India by a relative of the family. Chances are we will never discover the cause in this case. However, reading the increasingly confusing reports around the case does raise concerns that more extensive testing was not conducted at the time.

A further possible explanation might be provided by a Massey University PhD student's work.  Hayley Hunt of the Institute of Veterinary, Animal and Biomedical Sciences is investigating a rare disease in hunting dogs called Go Slow. The disease affects the dogs’ ability to walk by altering the mitochondria (energy-producing structures within cells), so that their muscles are no longer able to contract.  She says the likely cause of the disease is dogs eating wild pig meat that has been poisoned when the pig eats particular plants. The identity of the plant and toxin that may be tainting the pig meat is currently unknown and may be difficult to define, as there are so many possibilities.

Wild meat and botulism? Confusion reigns.

Recently in New Zealand, a family became seriously ill after consuming wild boar.  Authorities have said that the meat is suspected of being contaminated with botulin toxin.  Botulin is one of the most toxic substances on the planet.

I am somewhat confused by the reports - botulin toxin is produced by Clostridium botulinum growing in very low oxygen conditions.  The toxin is heat labile, i.e. it is destroyed by heating.  Apparently, the family ate curry made with the meat, and I would have expected the toxin to be destroyed by the cooking.  The family was reported to have collapsed within minutes of consuming the meal.  I'm not going to be dogmatic about this, but the toxin acts by binding to the nerve synapses, preventing release of actyl choline and thus blocking nerve impulse transmission.  Absorption of the toxin in the gut and transport to the synapses normally takes several hours, so the reported immediate collapse of the family is surprising.   As far as I am aware, there is no information on how long the cooked curry was held before consumption.  Spores of C. botulinum are extremely heat resistant, so if the curry were kept warm for a length of time before consumption, the spores could have germinated and produced toxin, though this implies quite a long time between cooking and consumption.

Health authorities have taken samples for testing and these have been sent to Australia - the tests are not simple, and results may not be available for several weeks.  However, the family is recovering in most cases, and anti-toxin has been administered.  Normally, recovery from botulinum intoxication takes weeks or months, not days.

Meanwhile, Ruapehu District Council has issued a warning over the health and safety of hunted and home kill meat.  It is illegal to sell hunted and home killed meat, but it can be shared with family, friends and visitors.  Again, this is confusing - if it can be legally consumed in this way, then there is no safety issue; it's a matter of regulations designed to ensure that meat offered for sale has been properly processed in an approved premises.  Further confusion arises because hunted and home killed meat can be consumed on a marae for traditional activities, but commercial operations on a marae must use commercially processed meat.

It seems to me that the toxicology report must be made available before conclusions can be drawn on the cause of this disaster for the family, and that reporters and regulators should be very careful to get their facts straight before publishing statements that can confuse the public further.