Shellfish Food Safety A new role to assist the industry

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Shellfish Food SafetyA new role to assist the
industry

• Dr Cath McLeod
• Senior Scientist (SARDI Shellfish Food Safety)

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NEW ZEALAND
AUSTRALIA
WELLINGTON
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My background

• Scientist routinely testing shellfish for toxins
  at ESR in NZ
• MSc and PhD on biotoxins and viruses in shellfish
• 8 years at the New Zealand Food Safety Authority
• Science advisor to the Scottish Shellfish
  Industry, particularly in the European scene

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Some work Ive been involved in

• Replacement of mouse test for DSP and NSP
• Market access negotiations for shellfish
• Formulating international guidance on regulation
  of new toxins
• Development of methods for virus detection in
  shellfish
• Industry submissions to regulatory agencies e.g.
  introduction of HPLC for PSP in the UK

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Shellfish food safety

• Shellfish - Natures filter
• Efficient concentrators
• One of the only farmed products that positively
  influences the environment!!!
• Often grown in inter-tidal locations
• Water quality critical

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Photo courtesy of Pristine Oysters, Coffin Bay,
South Australia
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International oyster food safety issues

• Viruses regulatory standard?
• Vibrio sp. regulatory standard?
• Marine Biotoxins lots of standards and probably
  more to come

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The Global Challenge
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Marine Biotoxins Key Considerations

• What biotoxins should we regulate?
• At what level should we regulate biotoxins?
• How should we test for biotoxins?

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Biotoxins are a complex problem

• Many many different toxic plankton
• Plankton flourish under different/unique
  conditions
• 9 different groups of toxins
• Within each group many different toxin conjenors
  e.g. gt 100 YTX analogues

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Risk assessments being undertaken by European
Food Safety Authority

• Okadaic acid lower level
• Saxitoxins lower level
• Yessotoxins raise level
• Pectenotoxins raise level
• Azaspiracids
• Cyclic imines start regulation, pinnatoxins?
• Palytoxin start regulation

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Palytoxin

• One of the most potent compounds known when
  injected into a mouse
• People get sick when they breathe in aerosols
  containing Palytoxin
• No confirmed illnesses from people consuming
  shellfish containing Palytoxin
• So why regulate???

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New symptoms of toxicity in mouse test
New species/ strain of algae
Human Illness Outbreak
Close Growing Area
New Class of Compounds
Information on symptoms of toxicity in
humans. Assay blood enzymes.
Set Tolerable Level
Dont Regulate
Toxicological studies Crude Toxin Extracts
Isolate and Identify Toxic Compounds
Oral Dosing with more Pure Toxin
Extracts (OECD 425)
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Mouse Bioassay for DSP toxins (OA, DTXs, PTXs,
YTXs, AZAs)

• 3 mouse, 24 hour observation time
• False negatives - does not detect all the toxins
  at the regulatory limit (0.16 mg/kg)
• False positives e.g. Free fatty acids,
  gymnodimine, others
• Animal ethics
• No validation

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Kiwi Bioassay
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NZs first validated LC-MS method

• Approved in 2001
• Detects approx 20 toxins (DAs, YTXs, PTXs, AZAs,
  OAs, DTXs)
• Some qualitatively
• Some quantitatively
• Industry driven

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Future work for me
The Problem
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Microbiological Indicator of Sanitation

• Approved by the USA
• Total coliforms (seawater)
• Fecal coliforms (seawater)
• Approved by the EU
• Escherichia coli (shellfish)
• South Australia
• Both seawater (FCs) and shellfish (E.coli) tested
  

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BUT// Human illness outbreaks

• Two human illness outbreaks (1970s) focused
  attention on the role of viruses in shellfish
  related outbreaks of gastroenteritis (UK - 700
  people and Australia - 2000 people). NoV.
• China, clams, HAV, 1988 (310, 000 people, 47
  fatalities)
• Louisiana oysters, NoV, 1993 (186, 000 people)
• Wallis Lake, HAV, 1997 ( 400 people)
• Current problem
• It remains unclear what the actual illness burden
  isgastroenteritis.reporting issues

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Norovirus

• Most common virus involved in shellfish related
  illness outbreaks
• Replicate in human intestine cells to produce
  gastroenteritis
• Low infectious dose e.g. NoV 5 viral particles
• Mainly transmitted person-person via faecal oral
  route
• Resistant to heat acid
• Persists for a long time in shellfish

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Key questions

• Once a shellfish growing area has been impacted
  by adverse event (faeces) how long does it need
  to be closed?
• How long do viruses remain infectious in marine
  environment and shellfish?
• How do we monitor for viruses? Which indicators?

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Virus Standards in EU

• Last 10 years PCR based methods have been
  developed around the world EU CRL.
• EC legislation already states that when a
  standard virus method is available that virus
  standards will be introduced.
• Three potential situations in which virus
  standards/legislation could be applied
• Virus monitoring at the growing area level
• Virus monitoring at the processing level
• Virus criteria for end product

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Recommendationsfrom Seafood plus (23 mill)
2007/2008

• It is recommended that consideration should be
  given to the introduction of end-product testing
  of shellfish imported into the EU for NoV and
  HAV.
• Categorisation of imports/countries likely to be
  via risk assessment

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NoV testing trend internationally

• Singapore - NoV monitoring programme required for
  frozen oysters
• Japan - testing imports
• Scotland - FSA sanitary survey, industry testing
• NZ, NSW - NoV testing for re-opening areas

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Photo courtesy of Pristine Oysters, Coffin Bay,
South Australia
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Photo courtesy of Pristine Oysters, Coffin Bay,
South Australia
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Photo courtesy of Pristine Oysters, Coffin Bay,
South Australia
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My work priorities (1)Norovirus project (3
years)

• Aims
• To provide data and a document to show that
  Norovirus in oysters is a low risk in SA
• To minimise any Norovirus monitoring requirements
  that get introduced in the future
• Project will include
• Method dev/validation
• Survey
• Risk assessment

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My work priorities Vibrios (2)

• Codex suggesting that there should be monitoring
  for vibrios at harvest to determine risk
• Singapore testing for vibrios
• EU considering what to do
• No levels set in codex yet, but experts say there
  will be in the nearish future
• No international standard methods to detect
  pathogenic vibrios

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My work priorities - Vibrios(2)

• Possible vibrio methods project
• Aims
• To develop a method that determines pathogenic
  Vp, Vv and Vc in oysters.
• To validate the method and get the method
  standardised and internationally accepted.
• To use the new methods to confirm SAs low risk
  status
• Project to include
• An interlaboratory study with the USFDA, the EC
  CRL and other key countries credibility and
  (hopefully) market access ease

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My work priorities (3) Diagnostic Capability
Mapping

• Aims
• To give CRC participants access to a full range
  of shellfish test methods to enable rapid
  response to issues and minimise trade
  disruptions.
• Will include
• Providing an advisory service to CRC participants
  including the Oyster Consortium
• Identification of key gaps in capability
• Development of a strategy to fill the gaps

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My work priorities (3)Capability Mapping I
need your help!

• What problems is the oyster industry in SA
  facing?
• Can science assist the industry in overcoming the
  problems?
• I can help you develop and implement projects to
  resolve these issues the good news is that I am
  FREE!!

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My work priorities (4)Shellfish standards

• Improve industry input into
• ASQAP
• FSANZ
• AQIS
• Facilitate Australian input into
• Codex
• Import countries regulations market access
• In collaboration with the industry

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The vision

• A national shellfish food safety centre
• Core testing capabilities
• Codex
• Technical market access issues
• Domestic food safety issues
• A programme that continues to deliver nutritious
  and safe to eat shellfish, but more efficiently

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Contact me with your problems and ideas!

• Email mcleod.cath_at_saugov.sa.gov.au
• Phone [phone]
• Mobile [phone]
• Fax [phone]

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With thanks to.

• Jayne Gallagher, Seafood CRC
• Jan Lee, SAORC/SAOGA
• Rachel King, Oyster Consortium
• Brendan Guidera, Pristine Oysters
• Ken Lee, SASQAP, PIRSA
• Anthony Zammit, NSWFA
• Andreas Kiermeier, SARDI