The overall objective of this project is to improve our understanding of the disease threats associated with the imports of aquatic animal commodities to support policies to minimise the risk of pathogen entry via the commodity trade.
To achieve this, the project will review the import into England and Wales of commodities in aquatic animal species susceptible to diseases considered to be of priority (currently exotic to or non-endemic in England and Wales). This will include a review of the types of products imported (unprocessed, processed, types of processing ...), an analysis of the quantities of the respective products imported, of the pathways and destinations within England and Wales, and of processing taking place in England and Wales, which may carry a risk of pathogen release.
Furthermore, the project will investigate risks associated with specific commodities, where data are currently insufficient to assess the risk associated with these commodities. This will be achieved through reviews of published data and experimental studies. The project will also identify requirements on bio-containment for processing plants, which would process fish from disease outbreaks. The outputs of the project will inform Defra policy on commodity trade and requirements on processing plants to prevent pathogen release from commodities once they have arrived in the country.
Under current EU legislation, products derived from aquatic animals imported for human consumption are considered a safe commodity. England and Wales have, however, experienced a number of introductions of exotic pathogens, where imports of fish products have been proven or were likely to be associated with the introduction of the pathogen (e.g. outbreaks VHS (2006) and sleeping disease (2007) in rainbow trout farms).
Published data on the tissue distribution of pathogens, and more specifically, pathogen load in individual tissues, are very limited. Even less information is available, when the level of viable pathogen is concerned in tissues that have been exposed to treatments after slaughter of the animal (e.g. storage of commodities on ice or freezing, other processing, such as smoking, salt conservation).
This project aims to fill some of these data gaps through investigating pathogen load in susceptible species following a variety of treatments. The focus will be on pathogens and commodities considered to be the most relevant threat to farmed and wild aquatic animals of England and Wales. VHSV is considered one of the most relevant and real threats. One of the main areas of experimental work within this project will therefore assess risks associated with the import of commodities that may carry viable VHSV.
Some of the imported commodities are further processed in England and Wales. Waste generated from such processing and water used in the process might be released. The location of processing sites in England and Wales will be investigated and bio-containment practices applied assessed. This will allow identifying the likelihood of exposure of aquatic animals to pathogens carried in imported commodities.