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PROJECT NUMBER • 2015-505
PROJECT STATUS:
COMPLETED

Identifying opportunities for developing community supported fisheries in South Australia’s small scale, multi-species, multi-gear community based fisheries

PIRSA with the support of Dr Joshua Stoll held several workshops and meetings with commercial fishers in the South Australian Lakes and Coorong Fishery (LCF) and Marine Scalefish Fishery (MSF), members of Wildcatch Fisheries SA and fish markets to understand whether the concept...
ORGANISATION:
Department of Primary Industries and Regions South Australia (PIRSA)
TAGS
Supply Chain
Resource Access And Allocation
Rac Sa
Fisheries Management
Community
Industry
PROJECT NUMBER • 2018-090
PROJECT STATUS:
COMPLETED

Improving early detection surveillance and emergency disease response to Pacific Oyster Mortality Syndrome (POMS) using a hydrodynamic model for dispersion of OsHV-1

Rapid predictive capability of viral spread through water during an aquatic disease outbreak is an epidemiologist’s dream, and up until now has not been achievable. A biophysical particle tracking model for Ostreid herpesvirus 1 microvariant (OsHV-1) that causes POMS was developed to determine...
ORGANISATION:
Department of Primary Industries and Regions South Australia (PIRSA)
TAGS
Oceanography
Mortality
Modelling
Fisheries Management
Ecosystem
SPECIES
Pacific Oyster
People

Environmental risk factors that may contribute to vibrio outbreaks - A South Australian case study

Project number: 2021-097
Project Status:
Completed
Budget expenditure: $59,100.00
Principal Investigator: Stephen Pahl
Organisation: Department of Primary Industries and Regions South Australia (PIRSA)
Project start/end date: 30 Jun 2022 - 30 Oct 2022
Contact:
FRDC
SPECIES
Pacific Oyster

Need

Vibrio parahaemolyticus can live in sediments and waters year-round and generally proliferates in the water column when water temperatures are greater than 14degC. V. parahaemolyticus are rarely isolated from seawaters below 10degC, though some cold-tolerant strains have been isolated overseas. The concentration of V. parahaemolyticus in the water column increases as the water temperature increases. Oysters naturally accumulate and depurate V. parahaemolyticus through filter-feeding, but once oysters are no longer underwater depuration can no longer occur and V. parahaemolyticus levels increase quickly unless the oysters are less than 10degC. Recent outbreaks in South Australia have been very unusual in that they have occurred in winter-spring. Other environmental factors including salinity, chlorophyll and turbidity have also been linked to vibrio prevalence, but relationships are inconsistent. Internationally some growing areas have established relationships between V. parahaemolyticus and other environmental parameters such as suspended matter, chlorophyll a and dissolved organic carbon, although this varies between areas and is not consistent.

Little is known around why outbreaks have begun occurring in Australia and Vibrios are an increasing risk to commercially produced oysters in Australia. The prevalence of vibriosis is globally linked to the effects of climate change, aging populations, dietary changes and improved detection methods. It is vital that all available relevant environmental data associated with these recent outbreaks is recorded and made available for future interrogations. The identification of data gaps and tools that could be used to identify and assess potential vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex and emerging food safety issue in Australia. This project is important to help defend current demand, consumer trust and safety in oysters.

Objectives

1. To collate and record all available environmental conditions (pre- and post-harvest) associated with the recent vibrio outbreaks in South Australia
2. To review the environmental conditions which may have been risk factors contributing to the recent vibrio outbreaks in South Australia
3. To review available tools that could be used to identify and assess potential vibrio risk factors and any approaches for improved surveillance
4. Recommendations on data and information collection deficiencies related to the South Australian situation

Final report

ISBN: 978-1-876007-54-6
Authors: Stephen Pahl Navreet Malhi Hugo Bastos de Oliveira Alison Turnbull
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 

Project products

Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Final Report • 2024-07-01 • 12.61 MB
2021-097-DLD.pdf

Summary

Vibrios are naturally occurring bacteria that are ubiquitous in fresh, estuarine and marine environments. Many Vibrio species are non-pathogenic, but some can cause disease in animals, and others are pathogenic to humans. People can contract vibriosis by consuming raw, undercooked or cross-contaminated seafood (predominantly oysters, crabs and shrimp) or exposing a wound to seawater. Bivalve molluscs, such as oysters, are a known vector for pathogenic bacteria as they are often consumed raw, and their filter feeding action concentrates bacteria within their tissues. Historically Vibrio parahaemolyticus has been rarely implicated in illnesses attributed to the consumption of Australian seafood. However, several recent outbreaks of gastroenteritis caused by V. parahaemolyticus in oysters have occurred in Australia.
 
An improved understanding of the environmental determinants was warranted to assist in future risk management considerations and food safety requirements. This report describes the results of the study undertaken which recorded the available and relevant environmental information and considered known risk factors relevant to V. parahaemolyticus that could be used for future investigations and to help underpin risk management considerations. The identification of data gaps and tools that could be used to identify and assess potential Vibrio risk factors may help guide where additional effort is required to assist future understanding of this complex food safety issue.
 
Vibrios are part of the normal microbiota of many oysters and are ubiquitous in many other aquatic products. Vibrios multiply in oyster tissues at temperature-dependent rates before, during and after harvest. Across the two outbreaks, three sequence types (ST36, ST50 and ST417) were identified from clinical isolates and only one sequence type (ST417) was isolated from oysters as part of investigations following the second outbreak. The environmental conditions, notably sea surface temperature, oyster basket temperature and salinity, during the onset periods of the two Vibrio outbreaks (February 2021 and September 2021) were conducive to the growth of V. parahaemolyticus. However, there were no evident climatological anomalies in the collated data sets that help to substantiate why these Vibrio outbreaks occurred in South Australia at these times given that there had not been any significant changes in oyster production, harvest and post-harvest practices. 
 
This project has also highlighted several data gaps. Poor traceability through supply chain hampered traceback investigations and the identification of the unique harvest date, harvest location, and subsequent production, harvest and post-harvest conditions was limited. There is no information publicly available on the levels of detection of V. parahaemolyticus in the implicated oysters. The occurrence of these two and similar recent Vibrio outbreaks in Australia demonstrates that vibrios are a risk that requires effective control mechanisms. A range of tools and approaches are available that could be used to identify and assess potential risk factors and improved surveillance. These tools include in-situ data collection, remote sensing of the environment, microbiological sampling and molecular diagnostics. 
 
Recommendations
1. In-situ environmental monitoring is improved through use of loggers in more growing and harvest areas.
2. Further work needs to be undertaken within the supply chain to ensure that legislated responsibilities on labelling, traceability and control of co-mingling are adhered to.
3. Vibrio parahaemolyticus isolates should be collected during vibriosis events (clinical and oyster) and an Australian isolate collection curated and maintained.
4. A review and refresh of growers recall plans is necessary and growers should participate in simulation training of recall events to improve the practices supporting speedy recalls.
5. Open lines of communication between regulators and industry should be maintained to determine what type of data can be shared and when.
6. Authorities should implement timely closure of growing areas following multiple illnesses in line with ASQAP guidelines.
7. Food Safety Management plans should be reviewed and closely adhered to, especially if there are any future outbreaks.
8. Regulators should hold a post event review that includes industry and research representatives to strengthen working relationships and improve joint outcomes. 
Fact Sheet • 2025-01-15 • 388.29 KB
2021-097-summary.pdf

Summary

Vibrio parahaemolyticus is a bacteria commonly found in estuarine and marine environments and can cause foodborne illness through the consumption of raw or undercooked seafood.
Scientific information on key pathogenic Vibrio species, their ecology, environmental risk factors and potential mitigation strategies were reviewed for two Vibrio parahaemolyticus outbreaks that were traced back to Pacific oysters produced in South Australia. The first outbreak commenced in March 2021 and the second outbreak started in September 2021.
A range of tools and approaches are available which can be used to identify and assess potential Vibrio risk factors and improved surveillance. These include local and remote-sensing of the environment, microbiological sampling and molecular diagnostics.
 
Industry
PROJECT NUMBER • 1999-332
PROJECT STATUS:
COMPLETED

Development of a national biotoxin strategy

In Australia aquaculture and wild harvest of shellfish is an economically important and growing industry. The safety of these products as a food source is of utmost importance from both public health and economic points of view. One of the potential problems faced by shellfish growers is...
ORGANISATION:
Department of Primary Industries and Regions South Australia (PIRSA)
TAGS
Workforce
Nutrition
Market Opportunities
Fisheries Management
Estuarine
SPECIES
Tropical Abalone
Ballot's Saucer Scallop
Blacklip Abalone
Roe's Abalone
Greenlip Abalone
Blank
PROJECT NUMBER • 2019-085
PROJECT STATUS:
COMPLETED

National Snapper Workshop - Rebuilding our iconic Snapper stocks

The Department of Primary Industries and Regions organised and ran a national Snapper Workshop in Adelaide from the 12 to 14 November 2019 with funding from FRDC and the strong support of the Australian Fisheries Managers Forum. The workshop objectives were to: identify key issues and...
ORGANISATION:
Department of Primary Industries and Regions South Australia (PIRSA)
TAGS
Workshop
Workforce
Stock Assessment
Stakeholder
Resource Rehabilitation
SPECIES
Snapper

PIRSA Innovative Solutions: Investigations to address key policy gaps associated with the development of clam farming in South Australia: genetic and health issues aligned to translocation and stock identification

Project number: 2010-233
Project Status:
Completed
Budget expenditure: $74,779.00
Principal Investigator: Xiaoxu Li
Organisation: Department of Primary Industries and Regions South Australia (PIRSA)
Project start/end date: 21 Dec 2011 - 29 Nov 2012
Contact:
FRDC
TAGS
Stock Assessment
Innovation
Disease
Biotechnology
Biosecurity

Need

The need for the development of an Australian clam aquaculture industry is a direct outcome of the inability of the wild clam industry to meet the demand of a large international market prepared to pay a premium price for quality Australian clams. While clam aquaculture has been successfully developed on a large scale overseas, none exists in Australia at this time. Currently, a feasibility study to evaluate clams culture on intertidal and subtidal leases in SA is underway with the funding support from FRDC, SA Clam Aquaculture and SARDI (FRDC project 2009/208).

At the same time, PIRSA Fisheries and Aquaculture is evaluating policies related to clam aquaculture development in SA to ensure the long term viability of both the wild harvest fishery and the successful development of a sustainable aquaculture industry. The critical knowledge gaps identified for this assessment are: 1. population genetic structure of clam species in South Australia; 2. potential genetic and biosecurity risks of moving farming stocks between localities, and 3. effective and efficient methods to distinguish hatchery produced stock from wild stocks. Understanding the population structure of this clam species and biosecurity risks of moving stocks will allow for the development of far more specific management strategies to control the potential adverse genetic and biosecurity impacts of farmed clams on the local wild population, thus protecting its genetic integrity if genetically divergent localised populations exist along the SA coastline. Practical identification of hatchery stocks will ensure compliance with wild fishery, aquaculture and recreational harvesting policies. All these need to be taken into account in developing clam aquaculture in SA.

Objectives

1. To characterise the genetic population structure of clams, Donax deltoides or Katelysia rhytiphora (to be determined) in South Australia
2. To identify and evaluate method(s) for differentiation between farmed and wild clams
3. To identify potential biosecurity issues relating to commercial clam aquaculture
4. To identify practical ways to mitigate unaddressed risks associated with clam aquaculture development in SA

Final report

ISBN: 978-1-921563-79-9
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Final Report • 2015-06-10 • 1.27 MB
2010-233-DLD.pdf
Environment
PROJECT NUMBER • 2003-220
PROJECT STATUS:
COMPLETED

Innovative Solutions for Aquaculture: potential for parasite interactions between wild and farmed kingfish, discrimination of farmed and wild fish and assessment of migratory behaviour

This project greatly contributed to an increased understanding of parasite fauna of yellowtail kingfish in Australian waters. This baseline information is critical to understanding potential parasite interactions between wild and farmed kingfish. Our risk assessment enables consideration...
ORGANISATION:
Department of Primary Industries and Regions South Australia (PIRSA)
TAGS
Tagging
Migration
Disease
Depredation
Biofouling
SPECIES
Yellowtail Kingfish
Industry
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