Ebola is by far one of the most ferocious viruses in the world. It has been raging in West Africa since 1976, with a mortality rate of up to 90 per cent. In the fish world, fish are also infected with Ebola-like viruses. The virus is highly contagious in fish, has a high lethality rate, is difficult to eradicate, and has long threatened the culture of food fish such as salmon.
In the autumn of 1984, a new disease was discovered in Atlantic salmon farmed off the southwest coast of Norway. The disease is called infectious salmon anaemia, or ISA virus for short. It spreads slowly, but has a fatality rate of up to 80%. By June 1988, it was widely disseminated and even attracted the attention of the Norwegian Food Safety Authority (NFSA).
In the summer of 1996, a similar disease occurred at salmon farms in New Brunswick, Canada. Fish mortality rates from affected farms are high, a disease known as "hemorrhagic kidney syndrome" (hemorrhagic kidney syndrome).
After research by Norwegian and Canadian scientists, both diseases originate from the same virus ISA.
Since then, the virus has appeared many times, from 1998 to 2016, in Canada, Norway, Chile, the United Kingdom and many other fish farms.
In one of the more serious ones, the outbreak of isa in southeastern Canada, Nova Scotia, in 2012, resulted in the destruction of more than 1.2 million salmon.
On 8 May 2014, isa virus was detected in two batches of chilled Atlantic salmon imported from Norway in Shenzhen Bay, China. At one point, the import trade in Norwegian salmon was banned.
Although the Canadian Food Inspection Agency has stated that salmon infected by ISA does not affect human consumption, in order to prevent the further spread of fish viruses, and the chain reaction caused by them, various countries are very strict in testing for such viruses.
Once the fish are infected with the ISA virus, there is no way to treat it. ISA has been ranked by the European Union as the number one disease affecting fish health. Not only does it have an impact on aquaculture, but it also threatens the survival of wild Atlantic salmon populations.
Scientific studies have shown that infected salmon will produce corresponding antibodies if they survive infection. A vaccine is currently under development.
There are several strains of ISA, some are pathogenic and some are not. Around 1900, strains of the virus in Europe and North America diverged from each other.
One study showed that from 1879 when rainbow trout first brought from North America to Europe, there were many fish shifts across the Atlantic, which may have carried the ISA virus. At that time, fish from the two regions were exchanged. Therefore, it is not possible to determine where the specific source of the virus is at present.
Another study suggests that the virus was introduced to Norway between 1932 and 1959, with the original strain being a European subtype found in North America. The strains found in Chile were transmitted from Norway between 1995 and 2007.
Food that is infected with the virus is always daunting. Recent news that salmon has been contaminated with the new crown virus is also boiling.
<h1 class= "pgc-h-arrow-right" > can salmon still be eaten? </h1>
Dialectical analysis, the current high temperature of more than 100 degrees can inactivate most viruses including ISA virus, new coronavirus and the like, in theory, human consumption is no problem.
But we can't take it lightly, because in the process of raw fish treatment, there may still be pollution transmission.
On June 18, the National Health Commission issued the Guidelines for the Normalization of the Prevention and Control of the Novel Coronavirus Pneumonia Epidemic in Key Units and Key Places in Key Areas in Low-Risk Areas in Summer. Among them, there is guidance that after handling raw meat, poultry, aquatic products, etc., wash your hands with soap and running water for at least 20 seconds. Do not rinse raw meat products directly under the tap to prevent spillage contamination. Avoid rubbing your eyes and nose directly with your hands when you come into contact with fresh ingredients during purchase and production. And you have to cook the food thoroughly before you can eat it.
Therefore, it is still edible to eat, but it is necessary to eat more carefully.