There are few infectious agents contaminating the products being processed, or are present and reproduced particularly in shellfish under production, without triggering diseases among those with a living shell.
Shells act as a filter against infectious agents in the environment. There is a possibility that larvae from specific intestinal worms, particularly the species Anisakis sp which is found in caught whitefish, may infect humans also, provided such fish are eaten raw. As far as parasitic nodules on intestines and in filets of fish are concerned, the problem is of a more aesthetic nature.
One type of infectious matter that can occur in processed seafood products is the bacteria Listeria sp. These bacteria are environmental bacteria that contaminate products and may lead to disease in the consumer. In shellfish, viruses in particular, but also intestinal pathogenic bacteria such as salmonella sp, may theoretically occur.
Monitoring and measures
To avoid listeria bacteria in seafood products, correct production hygiene and disinfection routines are especially important, as is the monitoring of relevant bacteria in the premises and products. This shall be part of the enterprises’ own control routines. Should unacceptable levels of the bacteria be found in processed goods, the consignments would be removed from the sales chain.
Seafood products are often double-checked for Listeria sp. in connection with their export to a number of countries. The subject of infectious matter in shellfish and relevant measures will be especially dealt with.
The National Veterinary Institute and NIFES monitor through their programmes in case and impact of general microbiological parameters, chlostridium bacteria and listeria sp. in fish and seafood, salmonella sp., mould and toxins in fishfeed, virus and bacteria in shells, human pathogenic and zoonotic parasites in fish and seafood, exotic bacteria from imported seafood and antibiotic resistance in fish microbes. Parasitic nodules in organs or filets of caught whitefish are removed as part of quality routines carried out by the seafood companies.