Biosecurity

Snouting out the truth on FMD fragments in the pork floss

Terry Sim, August 12, 2022

DAFF’s first assistant secretary biosecurity animal division Dr Robyn Martin at the Senate hearing.

FOOT and Mouth Disease viral fragments in a processed pork floss product recalled from Melbourne supermarket shelves last month were never tested to confirm their viability, despite statements by government and industry leaders the particles were “not live”.

Shortly after the FMD viral fragments discovery was disclosed last month, government and industry leaders variously claimed the particles were “not live”, “almost certainly dead” and that “the test does not indicate live virus.”

Sheep Central was told last week that the viability of the virus from FMD viral fragments — whether they are live or not — can only be determined with a virus isolation test and a Senate inquiry hearing this week confirmed this was not done.

Products imported from infected countries are required to undergo processing steps described in the World Organisation for Animal Health Terrestrial Code to inactivate virus and render products safe, although viral RNA can still be detected as fragments, and would not be able to transmit the infection.

Pork floss is a dried meat product with a light and fluffy texture similar to coarse cotton. The pork floss product recalled in Melbourne was from China, where FMD is endemic, but the Department of Agriculture Forestry and Fisheries has not been prepared to state its findings on the heat treatment status of the pork floss before importation.

The department and CSIRO at a Senate hearing this week confirmed that at present no laboratory in Australia is authorised to attempt virus isolation testing to determine if viral fragments are viable. The Australian Centre for Disease Preparedness at Geelong can do so if there is an outbreak of FMD in Australia.  Under its current licence, the ACDP lab must destroy any products immediately viral fragments are detected.

Tested to identify, but not for viability

RRAT Reference Committee chair Senator Matt Canavan at the hearing on Wednesday.

Wednesday’s hearing in a Senate inquiry into the adequacy of Australia’s biosecurity measure and response preparedness, in particular to Foot and Mouth Disease and Varroa mite, was told the pork floss product recalled in Melbourne was “apparently mislabelled.”

DAFF’s first assistant secretary biosecurity animal division Dr Robyn Martin said the test used on the pork floss detected viral fragments and confirmed Rural and Regional Affairs and Transport Reference Committee chair Senator Matt Canavan’s understanding that no Australian lab is authorised to do virus isolation, although Geelong’s ACDP lab could.

“What we have said is that it (the test used) doesn’t detect live virus, so you are correct in that to detect live virus you have to try and grow the virus on cell culture and often that won’t work.

“We’ve tried that with African Swine Fever with the detection that we’ve had on a significant number of products … at times of products seized at the border 48 percent have tested positive for ASF,” Dr Martin said.

“With the pork floss that product, (it) was a product that had been apparently mislabelled and so that matter is under investigation.

“It was shelf stable, it was sitting on the shelf, so it had been highly processed,” she said.

“We do currently allow imports of pork floss commercially with an import permit, but it has to be heat-treated to a certain time and temperature, and because we didn’t have those records for that product, that product has been removed from the shelves.”

“For all exotic animal diseases, our samples are sent to the Australian Centre of Disease Preparedness, so that’s CSIRO in Geelong.”

The recalled pork floss product. Image – DAFF.

Dr Martin confirmed that the ACDP did not do a virus isolation test on the FMD fragments in the pork floss products.

“No senator, once they detect FMD viral fragments that product is destroyed.

“So I think what we’ve said is the test detects viral fragments, not live virus, and as I’ve explained, because this product was something that had been heat-processed, was shelf stable, then it would be very unlikely that it would have live virus,” Dr Martin said.

“Because anything that’s sitting on a shelf that doesn’t spoil, we know that it’s been highly heat treated, but we didn’t have the documentation and so that’s currently under investigation.”

ACDP director Dr Trevor Drew said FMD viral fragments “do not denote the fact that the meat is infectious,” but their detection demonstrated the high sensitivity of detection systems. The presence of the fragments is confirmed with a polymerase chain reaction test and he confirmed that the Geelong lab is not able at this time to perform the isolation test for Foot and Mouth Disease virus.

Dr Drew said the ACDP lab is technically able to do all the tests for the diagnosis of FMD listed in the AUSMAT plan, “but there are certain ones such as virus isolation and characterisation of the virus, strain typing for vaccine matching purposes.

“We are currently not able to do any of those, not for technical reasons, but simply because we don’t have the authorisation from the relevant authorities in Australia.”

Dr Drew said the ACDP would also have to import FMD reference strains from a world reference laboratory in the UK to do virus isolation tests.

“Realistically, I think it would be probably three to four weeks to get the reference strains to us, and another two weeks to validate and set it up in our laboratories and run the tests themselves.

“In such circumstances we would send the virus to the Pirbright Institute in the UK and they would do the typing for us—as I understand is currently the case for Indonesia.”

What DAFF and the Minister said about the FMD fragments

A DAFF statement released on 20 July said: “During a recent purchasing and testing campaign of food for sale in supermarkets around Australia, one sample tested positive for FMD and African Swine Fever viral fragments – the test does not indicate live virus. This sample was from pork floss offered for sale in Melbourne.”

DAFF also said the pork floss product was processed, “but investigations have not found evidence that the treatment was to Australia’s requirements.”

On 21 July, a DAFF departmental spokesperson said: “The test does not indicate live virus, but viral fragments.”

“Proper heat treating destroys the virus, but would not destroy the fragments.

“Viral fragments cannot infect pig and swill feeding is illegal in Australia.”

In an industry webinar on FMD on 20 July, Minister for Agriculture Murray Watt said it isn’t clear that the products had been imported appropriately and the biggest risk Australia faced was from FMD coming in via animal products.

After announcing the pork floss discovery, Mr Watt also told the ABC: “If pigs in Australia were to eat that (contaminated meat) that would be a risk of the virus then being transmitted to Australian pigs and potentially then to other animals as well. So that’s the nature of the risk.”

In the July 20 webinar, head of DAFF’s National Animal Disease Taskforce Dr Chris Parker — without stating why the viral fragments in the pork floss product were not detected at Australia’s border – said the Melbourne retail detection was part of the department’s normal post-border work.

“Now we have always assumed that products we are seizing at the border are infected – we’ve been testing those and some of those are infected and that’s what we would expect.

“What we would also expect to find is that in products that are imported from countries where there has been an appropriate treatment, like heat treatment, you may still find the odd viral fragment in those products.

“In this case, again, we found that, but what wasn’t clear to us was that these products had been imported appropriately and so in an abundance of caution, particularly given the situation we are in at the moment, we removed them from the shelves.”

Australia’s Chief Veterinary Officer Dr Mark Schipp told Victorian Country Hour the pork products with the FMD fragments were from countries that (Australia doesn’t allow meat imports from) and had been described as (being of) vegetable origin, but were of animal origin.

“It doesn’t necessarily mean that there’s infectious virus or that the virus has survived the food processing processes,” Dr Schipp said.

Dr Schipp also reportedly stressed to the ABC that the fragments found in the meat products were not live and posed no risk to human health.

“Those animals were infected with those diseases at the time of their slaughter.

“It doesn’t necessarily mean that there’s infectious virus or that the virus has survived the food processing processes,” Dr Schipp said.

Minister Watt also reportedly told the ABC at the time:

“What has been found is viral fragments, which are almost certainly dead,” he said.

“They’re not live virus and it doesn’t mean that we’ve got Foot and Mouth Disease in the country at the moment.”

In a press conference, Mr Watt emphasised the FMD viral fragments in the pork floss did not pose a threat to human health and that Australia remained FMD-free.

“Now at one level, these detections are very disturbing, that we see these viral fragments, not live virus, viral fragments, coming into the country via these animal products, but at another level, these detections show the borders are strong and that our biosecurity systems are working.”

In the 20 July webinar, Red Meat Advisory Council independent chair John McKillop emphasised that “the detection of FMD fragments doesn’t mean a live virus.”

“So there is a clear distinction there that these were fragments, not the virus itself – it may be, but there’s no evidence of that, so don’t sort of everyone get alarmed and think we have FMD in the country – there’s no evidence to say that we do.”

In a Linkedin post on July 20, (subsequently removed) DAFF secretary and director of biosecurity Andrew Metcalfe reiterated the “urgent recall” of Bake Pork’s grilled pork floss sold at Asian food retail outlets across Victoria, stating:

“Do not feed or expose this product to livestock or other animals under any circumstances.”

DAFF has declined to quantify the level of FMD risk that Mr Metcalfe’s comments indicate might exist with feeding or exposing the pork floss product to animals, except for a departmental spokesperson stating:

“Out of abundance of caution and given the lack of documentation on the product this pork floss has been removed from the shelves, and the import path is being investigated.

“Pig owners must not feed meat, animal products or imported dairy goods to their pigs. Swill feeding is illegal in Australia.”

So why was the FMD fragment testing method not explained earlier?

Minister Watt and the department today offered no explanation as to why they did not say that the FMD viral fragments had not been tested for their viability.

A departmental spokesperson said the department cannot comment on an active investigation.

“The test does not indicate live virus but viral fragments.

“Proper heat treating destroys the virus but would not destroy the fragments.”

Mr Watt offered a transcript of a 21 July ABC interview where he said that “when these types of products are made, they are heated in the manufacturing process, and that’s what normally kills the virus.

“So it’s not uncommon for a virus of some kind to be in these types of meat products, but it’s almost always killed through the heating process that goes on through manufacturing,” he said.

“So that’s why we’re confident that there is no live virus that won’t be able to get out more widely.”

Mr McKillop told Sheep Central today he understood that Australia was not currently able to do the test necessary to determine if the FMD fragments were live.

“My understanding is that what we’ve got now is a RAT test, as for COVID, and what we need to go to is a more definitive test.

“I knew they didn’t do the full test, all they identified were DNA fragments of FMD found there.”

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