SafeFish SAFETY FACT SHEETS

Assisting the industry to resolve technical trade impediments in relation to food safety and hygiene.

Page 1 Contents

About SafeFish 3 Amnesic 4 Ciguatera 6 Clostridium botulinum 8 Listeria monocytogenes 9 Escherichia coli 10 Hepatitis A Virus (HAV) 12 Poisoning 14 Norovirus (NoV) 16 Okadaic Acids/Diarrhetic Shellfish Poisons 18 ABOUT SAFEFISH WHAT WE DO SafeFish provides technical advice to support SafeFish supports the resolution of issues and Paralytic Shellfish Poisons (Saxitoxins) 20 ’s seafood trade and market access challenges relating to the export, import and domestic Salmonella 22 negotiations and helps to resolve barriers to trade. It trade of Australian seafood products. It does this by Staphylococcus aureus 24 does this by bringing together experts in food safety undertaking the following key functions: and hygiene to work with the industry and regulators Toxic 26 • Developing technical advice for trade negotiations to agree and prioritise technical issues impacting on to assist in the resolution of market access and Vibrio 28 free and fair market access for Australian seafood. food safety issues. Wax Esters 30 SafeFish has a record of success in reopening • Developing technical briefs on high priority markets and in responding quickly when issues arise. codex issues. Contact SafeFish 32 By involving all relevant parties in discussions and, • Facilitating technical attendance at high priority where necessary, commissioning additional research Codex meetings and specific working groups. to fill any knowledge gaps, an agreed Australian • Identify & facilitate research into emerging market position is reached that is technically sound and access issues. defensible. This robust process builds knowledge and relationships, and results in better outcomes • The provision of technical information and advice to support emergency incident for industry in maintaining fair market access and ensuring that the seafood they sell is safe. response management. INTRODUCTION This SafeFish resource contains a collection of informative fact sheets for a number of food safety hazards that may affect seafood in Australia. These

sheets include a short summary on the hazard, its prevalence of outbreaks in Australia, the dose required to cause illness, the symptoms associated with illness, inactivation and prevention strategies, detection methods and the Australian regulatory Important Notice: Although SafeFish has taken all reasonable care in preparing this requirements for these hazards. This brochure report, neither SafeFish nor its officers accept any liability from the interpretation is also freely available on the SafeFish website or use of the information set out in this document. Information contained in this www.safefish.com.au. document is subject to change without notice.

Page 3 International regulatory limits can be found in the AMNESIC SHELLFISH POISONS Trade & Market Access Database, available at www. Domoic acid (DA) is a neurotoxin produced by a group of marine microalgae known as diatoms, mostly of frdc.com.au/trade. the genus Pseudo-nitzschia. The term “amnesic (ASP)” was coined to describe domoic acid intoxication, from the observation that many of the victims of the outbreak were affected by memory MORE INFORMATION dysfunction. However, DA can cause a range of other severe neurological impacts, including chronic epilepsy, FAO 2004. Marine biotoxins. FAO Food And Nutrition and can be found in many other marine food , including crustaceans, tunicates, fish, mammals and Paper 80, Rome. Food and Agriculture Organization seabirds, as well as a range of gastropod and molluscs. of the United Nations. WHAT ARE THE CAUSATIVE ORGANISMS? memories following neurological damage), Hallegraeff G. M. 2003. Algal in Australian respiratory difficulty and coma. shellfish. In: Hocking, A. D. (ed.) Foodborne In Australia the known causative diatoms are from Microorganisms of Public Health Significance. Sixth the group ( WHAT CAN BE DONE TO REDUCE OR ed. New South Wales: Australian Institute of Food Pseudo-nitzschia seriata P. multiseries MANAGE THE RISK? and P. australis) and the P. delicatissima group. Science and Technology Inc. • DA is heat-stable and therefore not degraded or These species grow naturally in marine environments. Pulido, O. M. 2008. Domoic acid toxicologic destroyed by cooking, although some leaching When they are present in significant levels they may pathology: a review. :180-219 into cooking water may be expected. Marine drugs 6 cause a hazard, particularly in bivalve shellfish as US Food and Drug Administration: Fish and they are further concentrated through filter feeding. • Shellfish production in Australia requires adherence to algal biotoxin management plans Products Hazards and Controls Guidance – 4th edition WHAT OUTBREAKS HAVE OCCURRED? to control this hazard. Each state monitors 2011 http://www.fda.gov/food/guidanceregulation/ commercial shellfish areas for toxic in the guidancedocumentsregulatoryinformation/ The first DA outbreak occurred in Canada in 1987, water and/or toxins in the shellfish. Detection of seafood/ ucm2018426.htm when 107 people who had eaten DA-contaminated either factor above compliance levels results were sickened, four of whom became in mandatory closure of until comatose and subsequently died. Fourteen concentrations return to safe levels. individuals suffered long-term neurological damage. • Longer term depuration treatments may facilitate No reports of illness attributable to DA poisoning the elimination of domoic acid, but should be have been received in Australia. confirmed with chemical and/or biological testing. • Avoid consumption of crustacean tomalley Short-term fishery closures have occurred (“mustard”) during bloom events as crustaceans in due to excess Pseudo-nitzschia are known to concentrate domoic acid in the counts. In 2010 a toxic Pseudo-nitzschia bloom hepatopancreas. in Wagonga Inlet on the New South Wales far south coast resulted in a four-month • Public health authorities may caution or restrict harvesting closure. recreational shellfishing when waters are affected by toxic microalgal blooms. HOW MUCH DOMOIC ACID IS A HARMFUL DOSE? HOW CAN WE TEST FOR DOMOIC ACID? • Microscopy technique can be used to detect the A dose of about 1milligram of domoic acid per presence of potentially toxic diatoms in water kilogram body weight is thought capable of initiating samples. symptoms of poisoning, i.e. around 65 milligrams for • Antibody-based screening test kits or confirmatory a 65kg adult. This equates to 325 milligrams DA per chemical testing conducted by specialist kg of seafood in a 200g portion. analytical laboratories can be used to detect DA WHAT ARE THE SYMPTOMS? in seafood tissue samples. • Mild intoxication may involve only gastro-intestinal REGULATORY STANDARDS upset (nausea, vomiting, diarrhoea, gut pains). The Australian Regulatory limit for DA in bivalve • Symptoms of neuro-intoxication include molluscs is 20 milligrams per kg (http://www. headache, convulsive seizures, myoclonus foodstandards.gov.au/). State food safety regulators (involuntary, irregular muscle contractions), may apply this limit in the case of other seafood cognitive impairment and disorientation, products found to be contaminated with DA. anterograde amnesia (inability to lay down new

Page 4 Page 5 WHAT CAN BE DONE TO REDUCE OR HOW CAN WE MONITOR CIGUATERA? MANAGE THE RISK? Ciguatera is a foodborne intoxication caused by consumption of ciguatoxins: a group of stable, fat-soluble There is currently no technology that is reliable • It’s recommended to be aware of ciguatera high chemical toxins that are found in particular fish species which spend some or most of their life-cycle on coral and cost-effective for testing fish prior to sale or risk areas and species size limits. The reefs. Precursor toxins to ciguatoxin are produced by dinoflagellate microalgae, and then modified as they consumption for ciguatoxins. ’s schedule lists fish to avoid: high move up marine food chains, for example as herbivorous fish are eaten by small carnivorous fish, which are risk species (Chinaman or Chinaman Ciguatoxins in fish can be measured by some specialist in turn eaten by larger carnivorous fish. The transformed toxins that cause illness are mainly found in large Snapper, Tripletail Maori Wrasse, Red Bass, laboratories, but the analysis is expensive and carnivorous fish. Paddle-tail or Humped-back Red Snapper therefore currently only suitable for post-intoxication and Moray Eel), and specified fish from testing or research. Individual fish suspected of WHAT OUTBREAKS HAVE OCCURRED? • Joint and/or muscle pain, lassitude. high risk areas (listed), or above specified causing ciguatera cases or outbreaks should be size limits. retained or retrieved, and forwarded to local public Ciguatera is the most common food poisoning Symptoms can last for days, weeks, months health authorities. event related to finfish consumption in Australia. or (rarely) years following a single ciguatera • Ciguatoxins are heat-stable, so are not destroyed Numerous cases and outbreaks, including some fatal poisoning incident. by cooking or freezing. REGULATORY STANDARDS intoxications, have occurred in Australia over many • Ciguatoxins are tasteless and odourless, so fresh decades. These cases relate to both commercial and visually-appealing fish may be toxic. Current Australian seafood industry risk management and recreational catch and domestic and export • If neurological symptoms occur within 24 hours protocols involve restrictions on sale based products. Fish captured from coastal and oceanic of a , seek medical attention; request on maximum size limits, high risk species and waters in and the Northern Territory attending doctors inform public health authorities capture location. See the Sydney Fish Market schedule account for most cases and outbreaks of ciguatera if ciguatera poisoning is diagnosed. for details. from Australia. There are currently no regulatory limits in Australia for Several ciguatera source regions are known around ciguatoxin in seafood. the world, including the South Pacific, Hawaii, the The US Food and Drug Administration have recently set Caribbean and Gulf of Mexico, and the western action limits of 10 nanograms (ng) Pacific ciguatoxin Indian . and 100ng Caribbean ciguatoxin per kg fish tissue. HOW MUCH CIGUATERA IS A EU regulations state that containing HARMFUL DOSE? ciguatoxins should not be marketed. International regulatory limits can be found in the Ciguatoxins are highly potent and are capable of Trade & Market Access Database, available at www. initiating ciguatera poisoning in very low quantities. frdc.com.au/trade. Fish containing as little as one ten-thousandth of a gram of the most potent ciguatoxin per gram of fish MORE INFORMATION flesh may cause illness. Queensland Health food safety fact sheet: naturally WHAT ARE THE SYMPTOMS? occurring seafood toxins http://www.health.qld.gov. au/foodsafety/ documents/fs-37-sea-toxin.pdf Mild intoxication may involve only gastro-intestinal Stewart, I., et al., Emerging tropical diseases upset (nausea, vomiting, diarrhoea, gut pains) which in Australia. part 2. Ciguatera fish poisoning. resolves in a day or two. More severe poisoning may , 2010. cause one or more of the following neurological signs Annals of Tropical Medicine and Parasitology :557-71. and symptoms: 104(7) • Itching, which may be intense and unrelenting for Sydney Fish Market: schedule of ciguatera high- days or weeks. risk areas and species size limits http://www. sydneyfishmarket.com.au/portals/0/ciguatera_ • Alterations in sensory perception, where contact schedule.pdf with cold surfaces or taking cold drinks may provoke burning or electric-shock-like sensations. US Food and Drug Administration: Fish and fishery • Tingling or painful sensations in hands, products hazards and controls guidance – 4th edition feet or genitals. 2011 http://www.fda.gov/Food/GuidanceRegulation/ GuidanceDocumentsRegulatoryInformation/ • Dizziness, low blood pressure, Seafood/ ucm2018426.htm cardiac abnormalities.

Page 6 Page 7 CLOSTRIDIUM BOTULINUM LISTERIA MONOCYTOGENES Clostridium botulinum is a naturally occurring bacterium and is one of the most important pathogens in foods. It Listeria are naturally occurring that can be found in many environments including animals, soils, and can be characterised by its anaerobic growth requirements, ability to form heat resistant spores and potential for processing facilities. Listeria monocytogenes is the only type of Listeria that is pathogenic to humans. The capability growth across a wide range of temperatures. Some strains are capable of producing a potent neurotoxin that can of L. monocytogenes to grow at refrigeration temperatures increases the risk from this pathogen. cause severe illness in humans and animals. WHAT SEAFOOD PRESENTS A RISK? • Modern smooth surfaces and competent • Severe symptoms include lack of muscle drainage have been found to reduce the risk of WHAT STRAINS ARE CONSIDERED A RISK Seafood that possesses a long shelf-life is considered co-ordination, fatigue and respiratory impairment contamination. IN SEAFOOD? to present a higher-risk, for example . Listeria and failure. • Effective HACCP-based food safety programs. C. botulinum Type E is considered the most common HOW DOES SEAFOOD BECOME CONTAMINATED? form detected in freshly harvested seafood and WHAT CAN BE DONE TO INACTIVATE OR • Effective sampling plans for testing of is commonly associated with has been associated with illnesses due to seafood ELIMINATE C. BOTULINUM? L. monocytogenes in processing plants and processing environments and can persist in drains, L. monocytogenes consumption in other countries. • The first line of defence for products that are end products. floors and wet areas. Cross-contamination from these considered a risk is strict temperature control of the • Separation of raw and processed product to prevent WHAT SEAFOOD PRESENTS THE product by storage at temperatures at or below 3°C. areas is the usual source. HIGHEST RISK? cross contamination. • For canned product, temperature profiles should be WHO IS AT RISK? Packaging formats that contain environments that are • Good personal hygiene during processing in achieved during canning that will achieve a 12 log Some members of the population are considered conducive to anaerobic growth and allow production the factory. cycle reduction of . as high risk groups including pregnant women of the neurotoxin, such as improperly canned C. botulinum and their foetuses, neonates, the elderly and the HOW CAN WE TEST FOR L. MONOCYTOGENES? product, vacuum packaged and modified atmosphere • For lightly preserved and fresh product a 3% water immuno-compromised. Australian Standard method AS 5013.24.1-2009 for packaged seafood. phase salt content should be used. testing in food and HOW CAN WE TEST FOR C. BOTULINUM? WHAT OUTBREAKS HAVE OCCURRED? Listeria monocytogenes WHAT OUTBREAKS HAVE OCCURRED? stuff is based on ISO 11290-1:1996 method: Horizontal There have been no recorded outbreaks in There have been no documented cases of botulism There is no Australian standard method for testing method for the detection and enumeration of C. Australia attributed to in Australian-sourced Listeria from the consumption of Australian seafood. . However testing methods such as traditional Listeria . botulinum seafood; however, there have been recall events of monocytogenes Furthermore, there have been no documented reports culture, PCR and ELISA are available. contaminated product. There have been illnesses For export products the Department of Agriculture has of this organism in Australian seafood. Neurotoxin detection can be performed by associated with seafood overseas, including approved a number of rapid methods by using ELISA HOW MUCH C. BOTULINUM IS A mouse bioassay, immunoassays and DNA New Zealand. and PCR techniques. HARMFUL DOSE? based techniques. HOW MUCH L. MONOCYTOGENES IS A It is not uncommon to detect non-pathogenic The dose response of the botulism neurotoxin Listeria REGULATORY STANDARDS HARMFUL DOSE? species during the first stage of culture based testing. is unknown. There is no specific Australian limit forC. botulinum A harmful dose can range from 102 to 106 cells These may not be a concern from a safety and regulatory For neurotoxins of C. botulinum Type E (the most Type E in seafood. although, other countries such dependent on strain and human host. perspective unless further stages of the testing confirm common type associated with seafood), approximately as india and thailand do set limits for C. botulinum; WHAT ARE THE SYMPTOMS? these as L. monocytogenes. 10 micrograms (μg) of toxin is estimated to result in International regulatory limits can be found in the Symptoms of listeriosis can vary, but can include: REGULATORY STANDARDS death. However, the production of toxins depends Trade & Market Access Database, available at Australia has standards for on the strain, the numbers of spores present and the www.frdc.com.au/trade. • Influenza-like symptoms such as fever, headaches Listeria monocytogenes under the Australia New Zealand Food Standards storage conditions. and muscle aches. MORE INFORMATION Code for ready to eat processed fish and • Can be gastrointestinal illness – vomiting and WHO IS AT RISK? Bates, J. R. & Bodnaruk, P. W. 2003. Clostridium processed bivalve molluscs, available at diarrhoea, although this is less common. All consumers are susceptible to the neurotoxins botulinum. In: Hocking, A. D. (ed.) Foodborne http://www.foodstandards.gov.au. produced by , although the immuno- Microorganisms of Public Health Significance. Sixth ed. • Septicaemia – fever, chills, rapid heart rate, C. botulinum International regulatory limits can be found in the compromised, the elderly and young children may New South Wales: Australian Institute of Food Science breathing difficulties. Trade & Market Access Database, available at require less toxin to become ill. and Technology Inc. WHAT CAN BE DONE TO MANAGE www.frdc.com.au/trade. L. MONOCYTOGENES? WHAT ARE THE SYMPTOMS? Gram, L. 2001. Potential hazards in cold-smoked fish: • Educational efforts targeted at high-risk sectors of MORE INFORMATION • Initial symptoms include nausea, vomiting Type E. , Clostridium botulinum Journal of Food Science the population advising them against eating high Sutherland, P. S., Miles, D. W. and Laboyrie, D. A. and diarrhoea. 66, S-1082-S-1087. risk products. (2003). Listeria monocytogenes. In: Hocking, A.D. • Neurological symptoms following that begin with Bell, C. & Kyriakides, A. 2000. Clostridium botulinum: • Application of appropriate food processing (ed.): “Foodborne Micro- organisms of Public Health cranial nerve areas including eye, throat and a practical approach to the organism and its control in technologies to high risk products. Significance”. Sixth ed. New South Wales: Australian mouth, followed by paralysis of motor nerves down foods, Oxford, Blackwell Science. Institute of Food Science and Technology Inc. the body. • Effective cleaning and sanitation of processing areas. Particular care for floors, drains, walls, • Constipation and abdominal pain CAC/GL 61 2007 guidelines on the application of hollow rollers, conveyor strips, rubbers seals and persists throughout. general principles of food hygiene to the control of inaccessible areas in equipment and machinery. Listeria monocytogenes in foods. Page 8 Page 9 ESCHERICHIA COLI HOW CAN WE TEST FOR E. COLI? E. coli is a part of the normal microbial flora in the intestinal tracts of humans and other warm-blooded E. coli can be measured through a variety of laboratory animals. Most E. coli strains are harmless; however some strains are pathogenic. techniques that may be either culture based or DNA based. The technique chosen depends on the level Pathogenic strains are classified into specific groups based on the mechanism by which they cause E. coli of specificity required (i.e. whether you are looking disease and clinical symptoms. These groups include: for total E. coli or specific strains). DAFF provides • Enteropathogenic E. coli (EPEC) All categories of E. coli may be shed in the faeces different testing methods for general E. coli, E. coli of infected humans, creating the potential to be spread non-O157 (STEC) and O157:H7. • Enteroaggregative E. coli (EAEC) E. coli to other humans, animals and the environment. • Enteroinvasive E. coli (EIEC) E. coli is often used as an indicator of faecal pollution. REGULATORY STANDARDS • Enterotoxigenic E. coli (ETEC) The Shiga toxin producing (STEC) strains are The Australian regulatory limit for can be • Diffusely adhering E. coli (DAEC) E. coli E. coli often associated with more severe illnesses. These found in Section 1.6.1 of the Australia New Zealand • Enterohaemorrhagic (EHEC) E. coli belong to the EHEC group. Of these, O157:H7 is the Food Standards Code, available at http://www. most commonly reported in Australia. foodstandards.gov.au. International regulatory limits can be found in the WHAT OUTBREAKS HAVE OCCURRED? WHAT CAN BE DONE TO MANAGE Trade & Market Access Database, available at www. E. COLI IN SEAFOOD? frdc.com.au/trade. Infection with STEC is a notifiable disease in all Australian states and territories. Seafood was not Hazards from E. coli can be prevented by: MORE INFORMATION implicated in any Australian outbreaks between 1988 • Not harvesting from contaminated waters. DAFF. 2006. DAFF approved methods for and 2010. • Prevention of contamination during processing microbiological testing of meat and meat products HOW IS E.COLI TRANSMITTED? by Good Manufacturing Practice (e.g. wearing [Online]. Available: http://www.daff.gov.au/__data/ gloves and proper personal protection), good assets/pdf_file/0006/2157504/approved-methods- • Person-to person personal hygiene, proper sanitisation of food for-microbiological-testing.pdf. • Cross-contamination contact surfaces and utensils, and prohibiting FDA. 2012. pathogenic Escherichia coli group. • Consumption of contaminated food or water people that are ill from working in food operations. In: Bad Bug Book: Foodborne Pathogenic • Direct contact with infected animals • Adequately cooking seafood to eliminate Microorganisms and Natural toxins handbook. 2nd HOW MUCH E. COLI IS A HARMFUL DOSE? pathogens (e.g. heating to an internal temperature Ed. Center for Food Safety and Applied Nutrition of 72°C and maintaining for 1 minute). (CFSAN) of the Food and Drug Administration (FDA), Doses causing illness vary depending on the • Maintaining seafood below 6.5°C or above 49.4°C U.S. Department of Health and Human Services. specific group and the immune response of to prevent growth. E. coli FSANZ. 2013. Shiga toxin-producing individuals. The infectious dose (in healthy adults) Escherichia coli USE OF E.COLI FOR MANAGING SHELLFISH (STEC). In: Agents of Foodbourne Illness. 2nd Ed. ranges from 10-100 cells for EHEC to 10 million to 10 FOOD SAFETY? Food Standards Australia New Zealand, Canberra. billion cells for ETEC and EPEC. Due to their prevalence as gut flora, generalE.coli are WHAT ARE THE SYMPTOMS? used widely in shellfish growing area management as indicators of faecal pollution. They are used to Symptoms from STEC usually begin three to four classify production areas as to suitability for direct days after exposure and most patients recover within harvest, and to determine when the risks of faecal ten days. Infections may range from asymptomatic pollution are high, prompting closure of harvest (no clinical symptoms) or can cause: areas. In this case they are acting as indicators for a • Diarrhoea, abdominal , vomiting and fever. wide range of bacterial and viral pathogens that can • In some cases haemorrhagic colitis be difficult to monitor directly. (characterised by severe abdominal cramps and bloody diarrhoea). • Haemolytic uremic syndrome (a combination of anemia, low platelet count and acute kidney failure) which can result in death.

Page 10 Page 11 HEPATITIS A VIRUS (HAV) HOW MUCH HAV IS A HARMFUL DOSE? REGULATORY STANDARDS The infectious dose of HAV is low, presumed to be There are currently no formal regulatory criteria for Hepatitis A virus (HAV) is a human enteric virus which causes acute infectious disease of the liver, known as 10-100 virus particles. HAV. Codex has developed guidelines on how to hepatitis. Hepatitis is a generic term for inflammation of the liver and can also be caused by chemicals, drugs control viruses in foods, available at http://www. or other viral infections. HAV is a non-enveloped, spherical (approximately 30 nanometers (nm) in diameter), WHAT CAN BE DONE TO INACTIVATE OR codexalimentarius.org, and testing for HAV following positive stranded RNA virus. ELIMINATE HAV? high risk events is recommended. • Freezing and refrigeration does not significantly International regulatory limits can be found in the significant shellfish related outbreak of HAV occurred reduce viral load in shellfish. HOW IS HAV TRANSMITTED? Trade & Market Access Database, available at www. in 1988 in Shanghai, China, resulting in approximately • Depuration is ineffective in controlling frdc.com.au/trade. HAV spreads via the faecal to oral route, either by 300,000 cases of illness. viruses in shellfish. direct contact with a HAV infected person or by Australia has only reported one shellfish related • Pasteurisation of shellfish is unlikely to MORE INFORMATION ingestion of HAV contaminated food or water. outbreak of HAV; in 1997 consumption of inactivate HAV. C.A.C. 2012. Guidelines on the application of general accounts for approximately 5% contaminated from Wallis Lakes, New South • Human enteric viruses are very stable at low pH principles of food hygiene to the control of viruses of all HAV cases worldwide. HAV can enter the Wales, resulted in 444 illnesses, including one death. levels. A greater than 3 log10 inactivation of HAV in food. codex Alimentarius Commission, Food and aquatic environment from septic tank leachates, may occur at pH < 3; however, this may render Agriculture Organization of the United Nations, World boat discharges, sewage discharges and people WHAT ARE THE SYMPTOMS? the sensory quality of food unacceptable. Health Organization. defecating or vomiting into waterways. • HAV is an acute illness with moderate onset of • Ultraviolet (UV) irradiation is ineffective in reducing symptoms (fever, malaise, anorexia, nausea, FDA 2012. Bad Bug Book, Foodborne Pathogenic Filter feeding bivalve molluscan shellfish can acquire viral loads in or on food. abdominal discomfort, dark urine) and jaundice. Microorganisms and Natural Toxins, USA, Food and HAV from their aquatic environment. Other seafood • Cooking shellfish at temperatures exceeding Drug Administration. products may become contaminated via infected • The incubation period of HAV ranges from 90 °C for greater than 90 seconds is likely to workers during processing if good hygiene practices 15-50 days. significantly reduce the level of infectious HAV Grohmann, G. & Lee, A. 2003. Viruses, Food and are not followed. • Illness generally lasts for two months, but Environment. In: Hocking, A. D. (ed.) Foodborne can be longer. WHAT CAN BE DONE TO MANAGE Microorganisms of Public Health Significance. Sixth HAV IN SEAFOOD? WHAT SHELLFISH RELATED OUTBREAKS • HAV is shed in high quantities in the faeces of ed. New South Wales: Australian Institute of Food HAVE OCCURRED? infected people two weeks prior to the onset of • Regular sanitary/pollution source surveys of Science and Technology Inc. shellfish growing areas to identity potential faecal HAV has been widely linked to consumption symptoms, and for at least four weeks during ISO 2012. ISO/TS15216: Microbiology of food and inputs and manage harvests accordingly. of contaminated shellfish worldwide. The first symptomatic infection. animal feed - Horizontal method for determination of documented shellfish related outbreak of “infectious • Effective vaccination against HAV is possible. • Regulation of shellfish harvesting areas to ensure hepatitis A virus and norovirus in food using real-time hepatitis” occurred in Sweden in 1955. The most adequate periods of closure following a faecal RT-PCR. contamination event. • Use of extended relay periods to cleanse shellfish grown in poor or unknown water quality. • Prevention of contamination during processing of seafood through good hygiene and manufacturing practices. HOW CAN WE TEST FOR HAV? Only molecular biology (real time RT-PCR) methods are sensitive enough to detect and quantify HAV in shellfish. The limit of detection of the method is approximately 100 genomes per gram of shellfish gut. The method used cannot distinguish between infectious and non-infectious virus particles. Recently an ISO technical specification for the detection of HAV in shellfish was released (ISO/TS15216, 2012).

Page 12 Page 13 HISTAMINE POISONING localised skin inflammation, vomiting, diarrhoea, MORE INFORMATION abdominal cramps, of the face and low Scombroid food poisoning is caused by ingestion of histamine, a product of the degradation of the amino blood pressure. Lehane , L. and Olley, J. (2000). Histamine fish acid . Histidine can be found freely in the muscles of some fish species and can be degraded to poisoning revisited. histamine by enzymatic action of some naturally occurring bacteria. Severe symptoms include blurred vision, severe International Journal of Food , , pp. 1-37. respiratory distress and swelling of the tongue. Microbiology 58 (1-2) Emborg, J., Dalgaard, P. and Ahrens, P. (2006). however other implicated non-scombroid species WHICH TYPES OF FISH CAN BE IMPLICATED? WHAT CAN BE DONE TO MANAGE sp nov., a histamine- included Mahi Mahi, , Escolar, Anchovies Morganella psychrotolerans HISTAMINE IN SEAFOOD? producing bacterium isolated from various . The scombrid fish Scombridae( ) such as and and Australian Salmon. Both domestically harvested • Histamine levels can increase over a wide range are traditionally considered to present and imported fish have been implicated with disease. International Journal of Systematic and Evolutionary of storage temperatures. However, histamine , , 2473-2479. the highest risk. However, other species have also Illnesses occurred from seafood consumed both Microbiology 56 production is highest over 21.8°C. Once the been associated with histamine poisoning; e.g. from restaurants and also from in a home setting. Hungerford, J.M. (2010) Scombroid poisoning: A enzyme is present in the fish, it can continue to Anchovies, Sardines, Yellowtail Kingfish, Amberjack review. Toxicon, 56, 231-243. produce histamine at refrigeration temperatures. and Australian Salmon, Mahi Mahi and Escolar. HOW MUCH HISTAMINE IS A HARMFUL DOSE? • Preventing the degradation of histidine to 2012. Joint FAO/WHO Expert Meeting on the Public WHICH BACTERIA ARE INVOLVED? histamine by rapid chilling of fish immediately Health risks of histamine and other biogenic amines A threshold dose is considered to be 90mg/100g. after death followed by good temperature control from fish and Fishery Products. Rome, Italy: Food and A variety of bacterial genera have been implicated in Although, levels as low as 5-20mg/100g in the supply chain is the most appropriate Agriculture Organization World Health Organization. the formation of histamine; e.g. , could possibly be toxic, particularly in Clostridium control. Although, a novel strain of Morganella Hahn, S. and Capra, M. (2003). Fishborne Morganella, Pseudomonas, Photobacterium, susceptible individuals. has been demonstrated to possess the ability for illnesses: Scombroid and ciguatera poisoning. In: Brochothrix and Carnobacterium. WHAT ARE THE SYMPTOMS? growth at 0-2°C. Thus, temperature control may Hocking, A.D. (ed.): “Foodborne Microorganisms WHAT OUTBREAKS HAVE OCCURRED? not eliminate risks in all circumstances. of Public Health Significance”. Sixth ed. New South Initial symptoms resemble some allergic reactions HOW CAN WE TEST FOR HISTAMINE? Wales: Australian Institute of Food Science and In Australia, 38 outbreaks (148 cases) of Histamine which include sweating, nausea, headache and Technology inc. poisoning were reported between 1988 and 2010. tingling or peppery sensation in the mouth and throat. • There are several analytical techniques that Many of the outbreaks were associated with Tuna, have been described by the AOAC including: a Other symptoms include urticarial (), biological method (AOAC 954.04), a chemical method (AOAC 957.07) and a fluorometric method (AOAC 977.13). • Commercially available ELISA based kits can be used. • Histamine concentration can vary considerably between anatomical locations and this should be considered in sampling plans. REGULATORY STANDARDS The Australian regulatory limit for histamine can be found in Section 1.4.1 of the Australia New Zealand Food Standards Code, available at http://www. foodstandards.gov.au. Codex Alimentarius sets and also hygiene and handling limits for a variety of seafood products including sardines and -type products; ; salted and sprat; frozen finfish and products comprised of finfish; crumbed or battered fish and fish portions; boiled dry salted anchovies; and . International regulatory limits can be found in the Trade & Market Access Database, available at www. frdc.com.au/trade.

Page 14 Page 15 REGULATORY STANDARDS NOROVIRUS (NOV) • Infected humans excrete high levels of NoV in their faeces (≤1011 virus particles/g faeces) for There are currently no formal regulatory criteria for Noroviruses (NoV) are small, round (approximately 27-35 nanometers (nm) in diameter), non-enveloped up to two to three weeks, long after symptoms NoV in Australia. Codex Alimentarius has developed viruses which have a single stranded RNA genome. NoV are very diverse, with over 25 different strains which have ceased. guidelines on how to control viruses in foods, available infect humans. NoV strains are grouped into at least five different genogroups, of which genogroup I, II and IV HOW MUCH IS A HARMFUL DOSE? at http://www.codexalimentarius.org, and testing most commonly infect humans. Human NoV is the leading cause of non-bacterial worldwide. for NoV following high risk events is recommended. The median infectious dose of NoV is estimated to be Immunity to the virus is often short lived and new pandemics appear every two to three years. No effective International regulatory limits can be found in the very low (18 virus particles), although the probability vaccine to human NoV is currently available. Trade & Market Access Database, available at www. of becoming ill in susceptible individuals is frdc.com.au/trade. dose-dependent. HOW IS NOROVIRUS TRANSMITTED? WHAT OUTBREAKS HAVE OCCURRED? WHAT CAN BE DONE TO MINIMISE RISK? MORE INFORMATION NoV is highly contagious and spreads via the Between 2001-2010, 17 Australian outbreaks of • Freezing and refrigeration does not eliminate NoV. C.A.C. (2012). Guidelines on the application of faecal to oral route. Transmission can be person-to- suspected shellfish related NoV illness were reported • Depuration is ineffective in eliminating viruses general principles of food hygiene to the control of person, through contaminated surfaces or through to OzFoodNet. Recent Australian outbreaks reported from shellfish. viruses in food. Codex Alimentarius Commission, consumption of contaminated food and water. were in: Food and Agriculture Organization of the United • Cooking shellfish at temperatures exceeding Foodborne illness accounts for 12-47% of all NoV Nations, World Health Organization. • 2008 following consumption of oysters from the 90°C for greater than 90 seconds is likely cases worldwide. Kalang River (NSW) causing illness in 40 people; to significantly reduce the level of infectious Grohmann, G. and Lee, A. (2003). Viruses, Food and NoV can enter the aquatic environment via septic tank and NoV, although heating at 60°C for 30 minutes Environment. In: Hocking, A.D. (ed.): “Foodborne leachates, boat discharges, sewage discharges and • 2013 following consumption of oysters from and pasteurisation are not sufficient to Microorganisms of Public Health Significance”. Sixth people defecating or vomiting directly into waterways. causing illness in over 500 people. eliminate viruses. ed. New South Wales: Australian Institute of Food Once NoV enters the aquatic environment, bivalve Science and Technology Inc. shellfish accumulate the viruses through the act of WHAT ARE THE SYMPTOMS? WHAT CAN BE DONE TO MANAGE ISO 2012. ISO/TS15216: Microbiology of food and filter feeding. • The incubation period is 10 – 50 hrs and symptoms NOROVIRUS IN SEAFOOD? animal feed - Horizontal method for determination of generally last 24 – 60 hrs. • Regular sanitary/pollution source surveys of NoV is accumulated and retained within the digestive hepatitis A virus and norovirus in food using real-time • Vomiting (projectile in >50% of cases), stomach shellfish growing areas to identity potential faecal tissues of bivalves, persisting in tissues long after inputs and manage harvest accordingly. RT-PCR. bacterial indicators of sewage contamination are cramps, watery non-bloody diarrhoea, abdominal • Regulation of shellfish harvesting areas to ensure Patel, M.M., Hall, A.J., VIinje, J. and Parashar, U.D. detectable. Other seafood products may become pain, low grade fever (< 50% of cases) and adequate periods of closure following a faecal (2009). Noro-viruses: A comprehensive review. contaminated by infected workers during processing headaches. contamination event. , , 1-8. if good hygiene practice is not followed. Journal of Clinical Virology 44 • Use of extended relay periods to cleanse shellfish Teunis, P.F.M., Moe, C.L., Liu, P., Miller, S.E., grown in poor or unknown water quality. Lindesmith, L., Baric R.S., Le Pendu, J. and • Prevention of contamination during processing Calderon, R.L. (2008). Norwalk virus: How infectious of seafood through good hygiene and is it? Journal of Medical Virology, 80, 1468-1476. manufacturing practices. HOW CAN WE TEST FOR NOROVIRUS? Only molecular biology (real time RT-PCR) methods are able to detect and quantify NoV in shellfish. The limit of detection of the method is approximately 100 viral genomes per gram of shellfish gut. The method used cannot distinguish between infectious and non-infectious virus particles. Recently an ISO technical specification for the detection of NoV in shellfish was released (ISO/TS15216, 2012).

Page 16 Page 17 OKADAIC ACIDS/DIARRHETIC SHELLFISH POISONS REGULATORY STANDARDS MORE INFORMATION The Australian Food Standard maximum limit for DST FAO (2004). Marine Biotoxins. FAO Food and Nutrition and are also known as Diarrhetic Shellfish Toxins (DST’s). They Okadaic acids (OA) Dinophysistoxins (DTXs) in bivalve molluscs is 200 micrograms OA equivalence Paper 80, Rome. Food and Agriculture Organization are a group of chemically-related lipophilic toxins that can contaminate shellfish and other seafood items and per kg, available at http://www.foodstandards.gov. of the United Nations. cause acute gastro-intestinal illness in humans, often referred to as diarrhetic shellfish poisoning (DSP). au. State food safety regulators may apply this limit Hallegraeff, G. M. (2003). Algal toxins in Australian , an unrelated lipophilic toxin that is often detected with OA, is included in DST’s for regulatory in the case of other seafood products found to be Pectenotoxin shellfish. Hocking, A.D. (ed.): “Foodborne purposes in Australia, but there is some controversy over its to humans. contaminated with DSTs. International regulatory In: Microorganisms of Public Health Significance”. Sixth limits for DSTs vary. some countries may not include ed. New South Wales: Australian Institute of Food pectenotoxin, or may also have limits for Azaspiracid, • No fatalities have been reported. Science and Technology Inc. WHAT ARE THE CAUSATIVE ORGANISMS? Yessotoxin and Gymnodimine – related algal toxins • May present a risk of dehydration requiring fluid that do not cause diarrhoea. Prego-Faraldo M.V. (2013). Okadaic acid meet DSTs are produced by marine microalgae known and electrolyte replenishment, particularly in and greet: an insight into detection methods, as dinoflagellates. In Australia the known causative International regulatory limits can be found in the young children or the elderly. response strategies and genotoxic effects in marine species are , , Trade & Market Access Database, available at www. Dinophysis acuminata D. acuta D. • is a potent tumour promoter, invertebrates. , 2829-45. , and . Okadaic acid frdc.com.au/trade. Marine Drugs 11 caudata D. fortii Prorocentrum lima which raises concerns about the possibility of US Food and Drug Administration: Fish and fishery These species grow naturally in marine environments. harmful effects from chronic, low-dose exposure. products hazards and controls guidance – 4th edition When they are present in significant levels they may Such exposures are difficult to measure, so the 2011 http://www. fda.gov/food/guidanceregulation/ cause a hazard in bivalve shellfish as they are further concerns of public health agencies are currently guidancedocumentsregulatoryinformation/ concentrated through filter feeding. directed toward concentrations of OA in shellfish seafood/ucm2018426.htm. that cause acute gastro-intestinal illness. DST producing species are found in all states in Australia at various levels. WHAT CAN BE DONE TO MANAGE DSTS? WHAT OUTBREAKS HAVE OCCURRED? • Commercial shellfish production in Australia requires adherence to algal biotoxin management Outbreaks of gastro-intestinal illness suspected plans to control this hazard. Detection in to have been caused by consumption of pipis shellfish product of DSTs that exceed regulatory (Plebidonax deltoides) contaminated by heat-stable compliance levels results in mandatory closure of toxins have occurred in NSW. fisheries until toxin concentrations return to safe levels. A six-week shellfish harvesting ban was imposed • Relaying shellfish to uncontaminated areas may on leases in Smoky Bay, South Australia, after OA facilitate the elimination of DSTs, but should be toxins were detected following a dinoflagellate bloom confirmed with chemical and/or biological testing. in 2003. • Public health authorities may caution or restrict A permanent ban on recreational harvesting of pipis recreational shellfishing when waters are affected from the Ballina area is in place due contamination by toxic microalgal blooms. with OA toxins. • DSTs are heat-stable, so cooking will not HOW MUCH OKADAIC ACID IS A deactivate them. HARMFUL DOSE? HOW CAN WE TEST FOR DSTS? A dose of about 1 microgram (μg) per kilogram • Monitoring source water samples by microscopy (kg) body weight is thought capable of initiating to detect the presence of potentially toxic symptoms of DSP, i.e. around 65μg for a 65kg adult. dinoflagellates. This equates to 325μg OA per kg flesh in a 200g • Monitoring seafood tissues for DSTs either via portion of seafood. antibody-based screening test kits or confirmatory chemical testing conducted by specialist WHAT ARE THE SYMPTOMS? analytical laboratories. • Nausea, diarrhoea, vomiting, abdominal pain and headache are the characteristic symptoms. • Usually resolves by three days following consumption of contaminated shellfish.

Page 18 Page 19 PARALYTIC SHELLFISH POISONS (SAXITOXINS) WHAT ARE THE SYMPTOMS? REGULATORY STANDARDS • STXs block nerve conduction, manifesting as Saxitoxins (STXs) are a group of chemically-related neurotoxins produced by a group of marine microalgae The Australian regulatory limit for STX in bivalve respiratory distress due to partial paralysis of the known as dinoflagellates. The term “paralytic shellfish poisoning (PSP)” was coined to describe the molluscs is 800 micrograms STX equivalents per muscles necessary for breathing. illness and deaths caused by eating contaminated shellfish. Saxitoxins have also been found in fish, kg, available at http://www.foodstandards.gov. crustaceans, cephalopod molluscs and ascidians, as well as a wide range of filter-feeding, herbivorous and • Mild neurological symptoms encompass au. State food safety regulators usually apply this carnivorous gastropods. tingling or numbness around the lips or in limit in the case of other seafood products found to fingers and toes (paraesthesias), sensations be contaminated with STXs. of floating or weightlessness (dysaesthesias), WHAT ARE THE CAUSATIVE ORGANISMS? In Tasmania in 2011, one male was hospitalised or gastrointestinal upset (nausea, vomiting, International regulatory limits can be found in the following consumption of mussels. diarrhoea, gut pains). Trade & Market Access Database available at In Australia the known causative dinoflagellates are www.frdc.com.au/trade. Several anecdotal cases exist from the consumption • More severe poisoning may present with from the (most commonly Alexandrium genus of Tasmanian mussels during extensive blooms in functional weakness (impaired grip strength, , , and MORE INFORMATION A. catenella A. minutum A. ostenfeldii 1986 and 1993. staggering gait), difficulty breathing and signs of ) and . A. tamarense G ymnodinium catenatum acute respiratory insufficiency, e.g. cyanosis of FAO (2004). Marine Biotoxins. FAO Food and These species grow naturally in marine environments. HOW MUCH SAXITOXIN IS A the lips or fingernails. Nutrition Paper 80, Rome. Food and Agriculture When they are present in significant levels they may HARMFUL DOSE? • Severe STX intoxication can cause catastrophic Organization of the United Nations. enter the tissues of marine animals, mainly through acute respiratory failure and death by asphyxiation. A dose of about 1.5 micrograms of STX equivalents Hallegraeff, G. M. (2003). Algal toxins in Australian feeding behaviours. Being water soluble, STXs tend per kilogram body weight is thought capable of shellfish. Hocking, A.D. (ed.): “Foodborne to be found more in filter-feeders and planktivores, WHAT CAN BE DONE TO MANAGE In: initiating symptoms of saxitoxin poisoning, i.e. around Microorganisms of Public Health Significance”. but lower-level carnivores may bioaccumulate STXs SAXITOXINS IN SEAFOOD? 100 micrograms for a 65 kg adult. This equates to Sixth ed. New South Wales: Australian Institute of at levels that can be hazardous to humans. Bivalve Shellfish production in Australia requires adherence 500 micrograms STX equivalents per kg seafood in Food Science and Technology Inc. shellfish present the greatest risk. STXs have been to algal biotoxin management plans to control this a 200g portion. recorded from Tasmania, Victoria, South Australia hazard. Each state monitors commercial shellfish Turnbull, A., Harrison, R. and McKeown, S. (2013). and New South Wales. Note that this dose is a topic of some controversy areas for toxic algae in the water and/or toxins in the Paralytic Shellfish Poisoning in South Eastern amongst expert groups. It is calculated from shellfish. Detection of either factor above compliance Tasmania. Communicable Diseases Intelligence WHAT OUTBREAKS HAVE OCCURRED? published reports of mild symptoms of STX poisoning levels results in mandatory closure of fisheries until 37, 3. in individuals who may be particularly sensitive to Toxic blooms and associated seafood product toxin concentrations return to safe levels. US Food and Drug Administration: Fish the toxin/s, and is lower than the concentration of contamination has resulted in considerable economic and fishery products hazards and controls saxitoxins currently mandated as the safety level Relaying shellfish to uncontaminated areas may disruption to affected industries. guidance – 4th edition 2011 http://www. in Australia and most other countries. The current facilitate the elimination of STXs, but should be fda.gov/Food/GuidanceRegulation/ Fortunately, Australia’s regulatory oversight seems to regulatory level has been in operation for many confirmed with chemical and/or biological testing. GuidanceDocumentsRegulatoryInformation/ have been largely effective to date, as there are only decades, with a long history of protecting public Avoid consumption of crustacean tomalley Seafood/ucm2018426.htm a few anecdotal and case reports of relatively mild health from STXs in commercial shellfish. (“mustard”) during bloom events as crustaceans are human illness, all from non-commercial harvests. known to concentrate STXs in the hepatopancreas. Public health authorities may caution or restrict some commercial and recreational activities when waters are affected by toxic microalgal blooms. HOW CAN WE TEST FOR SAXITOXINS? • Monitoring source water samples by microscopy to detect the presence of potentially toxic dinoflagellates. • Monitoring seafood tissues for STX either via antibody-based screening test kits or confirmatory chemical testing conducted by specialist analytical laboratories.

Page 20 Page 21 SALMONELLA MORE INFORMATION Salmonella are facultative anaerobic, non-sporulating, Gram negative bacteria. The genus Salmonella Jay, S., Davos, D., Dundas, M., Franksih, E. and Sumner, J. (2011). Hazards affecting Australian consists of the two species Salmonella enterica and Salmonella bongori. S. enterica has six subspecies Lightfoot, D. (2003). Salmonella. In: Hocking, A.D. seafood. South Australia: Australian Seafood and 1,500 serotypes. S. enterica is a frequently reported cause of foodborne illness, occurring in both food (ed.): “Foodborne Micro-organisms of Public Health Cooperative Research Centre, Fisheries Research poisoning-triggered epidemics and in isolated cases. Significance”. Sixth ed. New South Wales: Australian and Development Corporation. Institute of Food Science and Technology Inc. HOW IS SALMONELLA TRANSMITTED? and fever. The symptoms can be mild to severe and may last between 5-7 days. are widely distributed in nature and Salmonella • Typhoid fever is caused by S. enterica Typhi can enter the aquatic environment, food and water and Paratyphi, which only occurs in humans. If through animals, domestic stock, poor sanitation and untreated, the fever can last for weeks; however, with inappropriate disposal of human and animal wastes. antimicrobial treatment patients recover within 10- Salmonella-related gastroenteritis has been 14 days. Effective vaccination against typhoid fever frequently linked with the consumption of is possible. contaminated fresh produce, raw meats, poultry, WHAT CAN BE DONE TO INACTIVATE OR eggs and dairy products. ELIMINATE SALMONELLA? A small number of outbreaks have been associated Salmonella can be killed by exposure to : with seafood. The presence of Salmonella in seafood may derive from contamination occurring in the • ≥60°C for 4-6 minutes, natural aquatic environment, in or during • ≥30% NaCl (salt) concentration, processing and storage. • Water activity of below 0.94, WHAT OUTBREAKS HAVE OCCURRED? • pH of less than 3.8, although this is dependent on the type of acid used, In Australia, only five outbreaks including 60 cases • A high concentration of chlorine. It has been found have been reported in relation to the consumption thatthis can achieve a 1 – 2.5 log10 reduction in of seafood. colony units per gram of food, and; Salmonella have been identified as a cause of • Irradiation, although effectiveness is seafood related outbreaks in the European Union, dependent on food product and the level of the United Stated and in other countries. The US pathogen contamination. FDA has demonstrated the presence of Salmonella WHAT CAN BE DONE TO MANAGE in a variety of fish and shellfish, including ready- to- SALMONELLA IN SEAFOOD? eat seafood products, seafood products requiring minimal cooking and shellfish eaten raw. • Good manufacturing practice. • Good hygiene practice. HOW MUCH IS A HARMFUL DOSE? HOW CAN WE TEST FOR SALMONELLA? The infectious dose of varies with both Salmonella There are several testing methods for in serotype and the contaminated food matrix. Salmonella foods. The recommended methods are based on Human trials suggest approximately 105 colony the International Standard (ISO 6579) and Australian forming units are required to infect healthy adults. Standard (AS 5013.10-2009). WHAT ARE THE SYMPTOMS? REGULATORY STANDARDS

S. enterica predominantly causes two The Australian regulatory limit for salmonella can distinct diseases: be found at Food Standard 1.6.1 (http://www. • Gastroenteritis or “food poisoning” caused foodstandards.gov.au/). by non-typhoidal Salmonella serotypes. It is International regulatory limits can be found in the characterised by sudden nausea, vomiting, Trade & Market Access Database available at www. abdominal cramps, diarrhoea, headache, chills frdc.com.au/trade.

Page 22 Page 23 STAPHYLOCOCCUS AUREUS MORE INFORMATION Staphylococcus spp are ubiquitous in the environment and can be found in food due to environmental, human FDA. 2012. Staphylococcus aureus. In: Bad Bug Stewart, C. M. 2003. Staphylococcus aureus and and animal contamination. Book: Foodborne Pathogenic Microorganisms and Staphylococcal Enterotoxins. In: Hocking, A. D. Natural Toxins Handbook. 2nd ed. Center for Food (ed.) Foodborne Microorganisms of Public Health is a Gram-positive, non-motile, spherical (cocci) shaped, non-spore forming bacterium that S. aureus Safety and Applied Nutrition (CFSAN) of the Food Significance. Sixth ed. New South Wales: Australian is responsible for almost all staphylococcal food poisoning. can grow under aerobic and S. aureus and Drug Administration (FDA), U.S. Department of Institute of Food Science and Technology Inc. anaerobic conditions, but is a poor competitor and is often outcompeted by other microorganisms. Health and Human Services. S. aureus is a versatile human pathogen capable of producing highly heat-stable enterotoxins that can cause gastroenteritis. FSANZ. 2013. Staphylococcus aureus. In: Agents of Foodbourne illness. 2nd ed. Food Standards Australia New Zealand, Canberra. WHAT FOODS ARE MOST AT RISK? • Fatalities from staphylococcal food poisoning are rare in the general population but have been Foods that require extensive handling during reported from other countries. preparation and are kept above refrigeration temperature (4°C) for extended periods after WHAT CAN BE DONE TO MANAGE preparation have an increased risk. S. AUREUS? • Prevention of contamination during processing WHAT OUTBREAKS HAVE OCCURRED? by good manufacturing practice (e.g. wearing gloves and proper personal protection), good Since 2001, there has been only one reported personal hygiene and proper sanitisation of food outbreak involving three cases of staphylococcal food contact surfaces and utensils. poisoning that was linked to seafood consumption. This outbreak occurred in 2006 and was associated • Avoid time and temperature abuse of food with the consumption of rolls. products, especially those that require considerable handling during preparation. S. AUREUS HOW MUCH IS A S. AUREUS HARMFUL DOSE? HOW CAN WE TEST FOR ? Enumeration of by enrichment isolation, or Staphylococcal enterotoxins are produced during the S. aureus selective enrichment isolation, may be achieved by exponential growth phase of . The intoxication S. aureus using either: dose of the enterotoxins is less than 1.0 microgram. This toxin level is typically reached when S. aureus • The Australian Standard direct plate count (AS populations exceed 105-108 colony forming units per 5013.12.1- 2004). The direct plating method is gram of food. However, in susceptible individuals (young suitable when S. aureus is expected to be greater children, the elderly and severely debilitated) ingestion than 100 colony forming units per gram of food. of 0.1-0.2 micrograms of enterotoxins is sufficient to • The Australian Standard most probable number cause symptoms. (AS 5013.12.3-2004). The most probable number procedure is recommended for surveillance of WHAT ARE THE SYMPTOMS? products expected to have a small population of and a large population of The onset of staphylococcal symptoms are usually S. aureus competing organisms. rapid (1-7 hours after ingestion) and in many cases acute. Symptoms commonly include: REGULATORY STANDARDS • Nausea, abdominal cramping, vomiting and Australian regulatory limit for S. aureus can be diarrhoea. found in Section 1.6.1 of the Australia New Zealand • In more severe cases, dehydration, Food Standards Code, available at http://www. headache, muscle cramping, and transient foodstandards.gov.au. changes in blood pressure and pulse rate International regulatory limits can be found in the may occur. Trade & Market Access Database, available at www. • The duration of illness usually lasts from only a frdc.com.au/trade. few hours to one day; however in some instances, hospitalisation may be required.

Page 24 Page 25 WHAT CAN BE DONE TO MANAGE TOXIC MORE INFORMATION TOXIC METALS METALS IN SEAFOOD? Berntssen M.H., Julshamn K., and Lundebye, A.K. WHAT IS ARSENIC? WHAT IS LEAD? • Metals in seafood tissues cannot be destroyed by 2010. Chemical contaminants in aqua feeds and cooking or processing. Arsenic is present in seafood mostly as an organic Lead causes harmful effects on the kidneys and Atlantic salmon (Salmo salar) following the use form, which is much less toxic than inorganic. Arsenic nervous system. Children are particularly sensitive • Fish meal is the principal source of toxic metals in of traditional versus alternative feed ingredients. farmed fish; alternative fish feeds produced from is a recognised human carcinogen. to the neurotoxic effects of inorganic lead because Chemosphere 78(6), 637-46. the blood-brain barrier is underdeveloped. Dietary vegetable sources can considerably reduce fillet FAO/WHO. (2011). Report of the joint FAO/WHO WHAT IS CADMIUM? exposure to lead occurs through a wide range of loads of arsenic and mercury. expert consultation on the risks and benefits of foods and beverages; some seafood products can • Toxic metals accumulate preferentially in Cadmium is widely distributed in the environment, fish consumption. Rome, Food and Agriculture contribute to lead intake. crustacean hepatopancreas, so processes and/ and can be found in many food items, including Organization of the United Nations; Geneva, World or advisories to eliminate or reduce consumption some seafood products. Cadmium is a carcinogen Health Organization, 50 pp. WHAT OUTBREAKS HAVE OCCURRED? of crab, or prawn “mustard” may and is toxic to the kidneys. be considered. FSANZ. (2011). . Food Standards Toxic metals are rarely found in seafood at • Toxic metals may be present at high levels in Australia New Zealand, Canberra. http://www. WHAT IS MERCURY? concentrations likely to cause outbreaks of acute some estuarine, coastal and marine waters foodstandards.gov.au/consumer/chemicals/ illness. Adverse human health effects arise from Mercury in organic form, particularly methylmercury, and food webs from both natural and human- mercury/pages/default.aspx. repeated, cumulative low-dose exposures from a is of greatest concern to public health. Methylmercury associated sources. Public health authorities may wide range of dietary and non-dietary sources, of International Programme on Chemical Safety. (2001). is fat-soluble, and therefore tends to be found in place controls or advisories around the collection which seafood consumption may in some cases be Environmental Health Criteria 224: Arsenic and higher concentrations in large carnivorous fish such of seafood, particularly shellfish and bottom a significant contributor. Arsenic Compounds. World Health Organization, as shark, swordfish and some tuna. Methylmercury dwelling fish, from these areas. Geneva. has harmful effects on the development of brain, so HOW MUCH TOXIC IS A HOW CAN WE TEST FOR TOXIC METALS? pregnant women and children are the main focus of HARMFUL DOSE? Satarug, S., Garrett, S. H., Sens, M. A. and Sens, D. seafood safety interventions. A. (2010). cadmium, environmental exposure, and Modern chemical methods can accurately detect and Doses of toxic metals from seafood consumption health outcomes. , quantify a range of toxic metals in seafood and water; Environmental Health Perspectives alone are unlikely to cause acute illness. Harmful , 182-190. several analytical laboratories offer these services. 118 concentrations of specific metals in particular food Inductively coupled plasma-mass spectrometry is items are assessed by food safety authorities based one of the more widely adopted methods. on information relating to typical consumption patterns and the known chronic health effects of REGULATORY STANDARDS exposure from dietary and other sources. National and international food safety agencies WHAT ARE THE SYMPTOMS? monitor and regulate specific seafood products for toxic metal levels. Maximum allowable levels Overt of acute metal poisoning in Australia vary for different seafoods and can be are unlikely to be attributable to consumption of found at http://www.foodstandards.gov.au. seafood alone. Foetal and childhood exposure to methylmercury and/or lead may manifest as subtle International regulatory limits can be found in the but measureable dose-related cognitive impairment. Trade & Market Access Database, available at http:// www.frdc.com.au/ trade. Long-term excess exposure to particular toxic metals, from all sources (dietary and non-dietary), can cause: • Chronic renal failure, cancers of the breast, prostate and uterus, and bone disease – osteoporosis, osteomalacia and spontaneous fractures – associated with chronic ; and • Cancers of the skin, lungs, bladder and kidney, and chronic skin diseases – hyperkeratosis and dyspigmentation – associated with chronic .

Page 26 Page 27 VIBRIO Vibrio are naturally occurring marine bacteria that is found in most aquatic environments. Some species of this bacterial group are known to cause human illness.

WHICH SPECIES ARE HARMFUL WHAT TYPES OF ILLNESS CAN OCCUR? TO HUMANS? There are three distinct syndromes that can occur Although the majority of Vibrio species are considered from Vibrio infections: gastrointestinal illness, non-pathogenic to humans, some have been septicaemic infection and wound infections. The associated with human illness. The three species latter is not associated with consumption of seafood. widely regarded to be associated with human illness WHAT ARE THE SYMPTOMS OF V. CHOLERA Shellfish Industry Operations Manual, Sydney Rock Oysters must be stored at 25°C or less are: Vibrio parahaemolyticus, V. vulnificus and WHAT OUTBREAKS HAVE OCCURRED? (NON O1/O139) ASSOCIATED WITH THE . Several other species have also been CONSUMPTION OF SEAFOOD? within 24 hours of harvest and at 21°C or less V. cholera Illnesses associated with contaminated seafood associated with illness, either at a lower frequency or Vibrio within 72 hours of harvest. are rare in Australia. A total of 5 cases associated • Diarrhoea (bloody) and abdominal cramps. with less conclusive evidence: • Vibrios are highly susceptible to heat. with bivalve shellfish have occurred between 1992 • Fever, and although rarer in occurrence, Heating to greater than 65°C will inactivate • and 2013. One of these cases resulted in a mortality septicaemia can also develop in V. alginolyticus, pathogenic strains. • from V. parahaemolyticus. The remaining four cases compromised individuals. V. carchariae, • Appropriate adherence to regulatory temperature were associated with V. vulnificus and two of these • V. cincinnatiensis, WHICH SEAFOOD CAN BE controls is the best preventative measure. patients died. • CONSIDERED VECTORS? V. damsel, • Depuration is not effective in removing Vibrio from Two large outbreaks of (1990 • V. fluvialis, V. parahaemolyticus • Bivalve shellfish V.( parahaemolyticus bivalve shellfish. and 1992) were associated with imported prawns. and ). • V. furnissii, V. vulnificus HOW CAN WE TEST FOR VIBRIO? • V. hollisae, • Prawns/shrimp (V. cholerae). HOW MUCH IS A HARMFUL DOSE? • Microbiological analysis using selective media. • V. metschnikovii and • Finfish V.( parahaemolyticus). • Approximately 106 cells of V. cholera in • Identification of isolates by biochemical • . V. mimicus healthy adults. WHAT INCREASES THE RISK? phenotype or Polymerase Chain Reaction (PCR). • Approximately 2 x 105 - 3 x 107 cells of • Post-harvest temperature abuse throughout • PCR detection direct from enrichment cultures. V. parahaemolyticus in healthy adults. the supply chain can allow the growth of these REGULATORY STANDARDS • The dose of V. vulnificus for healthy people is pathogens in the seafood to levels associated unknown, but in at risk groups (see susceptible with illness. There is no standard set for Vibrio in the Australia individuals below) it may be less than 100 cells. • Susceptible individuals (the immuno- New Zealand food standards code. limits are set by several countries including (but not limited to) WHAT ARE THE SYMPTOMS OF V. compromised, those who suffer from liver PARAHAEMOLYTICUS disease and/or have excess levels of iron in Canada, China, India, Japan, Thailand the United ASSOCIATED WITH States of America. THE CONSUMPTION OF SEAFOOD? the blood serum) are at a greatly increased risk of septicaemia. • Severe gastrointestinal illness including diarrhoea, International regulatory limits can be found in the • Harvesting of seafood from areas of lower salinity which can sometimes be bloody, abdominal Trade & Market Access Database, available at www. can present a higher risk. pains, nausea and vomiting. frdc.com.au/trade. • In Australia, the prevalence of species is • Occasional septicaemic infection, only rarely Vibrio not well understood, and the relationship between MORE INFORMATION associated with mortality. temperature and salinity has not been explored. Desmarchelier, P.M. (2003). Pathogenic . in: WHAT ARE THE SYMPTOMS OF V. Vibrios WHAT DECREASES THE RISK? hocking, A.D. (ed.): “Foodborne Microorganisms VULNIFICUS ASSOCIATED WITH THE of Public Health Significance”. Sixth ed. New South • The Australian Shellfish Quality Assurance CONSUMPTION OF SEAFOOD? Wales: Australian Institute of Food Science and Program Operations Manual sets maximum • Primary septicaemia with symptoms of fever chills Technology Inc. storage temperatures for live bivalves post- and nausea may occur in susceptible individuals harvest to control the growth of indigenous Hudson, A. and Lake, R. (2012). Risk profile: e.g. immuno-compromised and can result pathogens. Shell stock must be placed under in ready-to-eat smoked fish in mortality. Clostridium botulinium ambient refrigeration at 10°C or less within 24 and shellfish in sealed packaging. Wellington, New • Gastroenteritis, which presents as vomiting, hours of harvest or depuration. Under the NSW Zealand: Ministry for Primary Industries. diarrhoea and abdominal pains.

Page 28 Page 29 WAX ESTERS WHAT ARE THE SYMPTOMS? REGULATORY STANDARDS • Oily diarrhoea is caused by accumulation of Wax esters are fatty acid components of certain types of fish. Wax esters are indigestible by humans and There is no regulation against the sale of Escolar indigestible fish oils in the rectum before being cause a condition known as steatorrhoea or, more specifically, keriorrhoea, in which anal leakage of an oily or Oilfish in Australia. Some state authorities, e.g. expelled, often involuntarily. residue occurs, sometimes accompanied by abdominal cramping, nausea and vomiting. Queensland, recommend a health warning about • Symptoms are not life-threatening, and the the risks of consuming these fish is displayed at the diarrhoea caused by wax ester consumption does point of sale. WHAT FISH SPECIES ARE WAX ESTERS WHAT OUTBREAKS HAVE OCCURRED? not result in dehydration or electrolyte imbalance. Regulatory intervention is highly variable FOUND IN? • Severity ranges from a painless discharge Reported outbreaks from consumption of wax internationally. Escolar and Oilfish are prohibited of oily yellow, orange or green liquid to more Wax esters are found in the fats of certain types esters are infrequent in Australia. One outbreak for import and sale in Japan, Italy and South Korea. intense diarrhoea, nausea, vomiting and of fish, and in particular Escolar ( was reported from New South Wales in 2001, where Other countries do not regulate these fish. Lepidocybium abdominal cramping. flavobrunneum) and Oilfish Ruvettus( pretiosus). delegates at a conference consumed mislabelled • Symptom onset ranges from hours to days Requirements for veracity and integrity in These two species contain very high proportions of Escolar for lunch. Of the 44 delegates interviewed following a single exposure. product labelling represent more widely-adopted indigestible wax esters. by public health officers, 20 reported symptoms. regulatory practices that can impact on the sale of Other cases and outbreaks have been reported from Fish mislabelling and misidentification has led WHAT CAN BE DONE TO MANAGE WAX Escolar or Oilfish. Victoria and South Australia. to instances where Escolar or Oilfish have been ESTERS IN SEAFOOD? International regulatory limits can be found in the incorrectly or fraudulently sold in Australia under • Cooking does not destroy or degrade wax esters. HOW MUCH WAX ESTER IS A Trade & Market Access Database, available at www. different names, such as Butterfish and Rudderfish. Some agencies recommend grilling in order to HARMFUL DOSE? frdc.com.au/trade. Escolar has been sold in other countries under separate oils from the flesh, but others dispute names such as Sea Bass, Cod, White Tuna and A single meal of Escolar or Oilfish is sufficient to such advice, suggesting that water loss from MORE INFORMATION Hawaiian Butterfish. cause gastro-intestinal symptoms. grilling or baking can concentrate the oil content. • Addressing the issue of fish mislabelling, Ling, H.K., Nichols, P.D., But, P.P.H. (2009). Fish- misidentification and substitution is an important induced keriorrhea. Advances in Food and Nutrition management intervention. Research 57, 1-52. HOW CAN WE TEST FOR WAX ESTERS? Queensland Health. (2011). Food Safety Fact Sheet No. 9: Escolar and Oilfish health warning http://www. • A rapid and inexpensive chemical test health.qld.gov.au/foodsafety/documents/fs-9- for detecting wax esters in fish has been oilfish.pdf developed overseas and could be adopted by Australian laboratories. Yohannes, K., Dalton, C.B., Halliday, L., Unicomb, • DNA barcoding can confirm the identity of L.E., Kirk, M. (2002). An outbreak of gastrointestinal fish species in cases where the provenance is illness associated with the consumption of Escolar uncertain or disputed. fish. Communicable Diseases Intelligence 26(3), 441-5.

Page 30 Page 31 CONSIDERING THE BENEFITS AND RISKS OF SEAFOOD CONSUMPTION

Eating seafood confers many benefits: it provides top-quality protein, and is an excellent source of important nutrients like iodine, , vitamins A and D, and long-chain polyunsaturated omega-3 fatty acids. However like all foods, some seafood products may contain substances that are harmful to health. Illness from seafood is rare, so the benefits of seafood consumption must be weighed against the risks. For most people, following the recommended national dietary guidelines is the best means of balancing risks and benefits. For some groups such as pregnant women and children, specific advisories on healthy and safe seafood choices should apply. For more information, please see: http://www.nap. edu/catalog/11762/seafood-choices-balancing- benefits-and-risks and http://www.foodstandards. gov.au/

For further information: SafeFish GPO Box 397, Adelaide, South Australia 5001 Fax: +61 8 8303 9424 Alison Turnbull – Program Manager Ph: +61 8 8303 9623 M: 0418 348 450 E: [email protected]

Natalie Dowsett – Executive Officer Ph: +61 8 8303 9399 M: 0407 604 027 E: [email protected] www.SafeFish.com.au