Infectious Salmon Anemia
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چکیده
Infectious salmon anemia (ISA) is one of the most important viral diseases of farmed Atlantic salmon. This highly contagious disease can be insidious, with an initially low mortality rate; however, the cumulative mortality can sometimes exceed 90% if the disease remains unchecked. Infectious salmon anemia was first described in Norway in 1984, and it continues to be a problem in that country despite control measures. Since the late 1990s, outbreaks have also been reported in other locations. This disease devastated the salmon industry of the Faroe Islands in 2000, and an epizootic in Scotland in 1998-1999 cost an estimated $32 million (U.S.) to eradicate. ISA has been a recurring problem in Chile, the Cobscook Bay in Maine, and the Bay of Fundy in New Brunswick, Canada. In New Brunswick, it results in annual losses of approximately $4.8–$5.5 million (U.S) to farmers, and millions of fish have been culled in control efforts. New outbreaks can also occur in areas where this disease was absent for many years. In 2009, an outbreak was reported again in Scotland. Understanding of the epidemiology of ISA is still incomplete, which complicates its control. The reservoirs for the virus are not known, but experiments have shown that several species of salmonids can carry virulent ISA viruses asymptomatically. These viruses might cause outbreaks if they are transmitted to farmed Atlantic salmon. Noncultivable, apparently nonpathogenic, isolates have also been detected in wild salmonids. Small changes in these viruses, analogous to the mutations that allow low pathogenicity avian influenza viruses to become highly pathogenic, may allow them to become more virulent. Some evidence suggests that certain ISA viruses may cause illness in species other than Atlantic salmon. One virus was isolated from sick farmed Pacific coho salmon in Chile in 1999, and a highly virulent strain can cause disease in experimentally infected rainbow trout.
منابع مشابه
Retraction: Characterization of Chinook head salmon embryo phenotypes of infectious salmon anemia virus by real-time RT-PCR
متن کامل
Characterization of the infectious salmon anemia virus genomic segment that encodes the putative hemagglutinin.
The genomic segment encoding the putative hemagglutinin of infectious salmon anemia virus (ISAV) is described. Expression of the putative hemagglutinin in a salmon cell line demonstrated hemadsorptive properties of the protein for salmon erythrocytes. The polypeptide was recognized by an ISAV-specific monoclonal antibody. Nucleotide sequencing indicated the occurrence of a variable region in th...
متن کاملInternational Response to Infectious Salmon Anemia: Prevention, Control, and Eradication
Although there are several detection techniques for infectious salmon anemia virus (ISAv), none of these assays has yet been validated by reference authorities, such as the Office International des Epizooties (OIE) or the National Veterinary Services Laboratories in Ames, IA. Each diagnostic test discussed herein has problems that confound straightforward pathogen detection, interpretation of r...
متن کاملShipping and the Spread of Infectious Salmon Anemia in Scottish Aquaculture
Long-distance transport of pathogens plays a critical role in the emergence of novel diseases. Shipping is a major contributor to such transport, and the role of ships in spreading disease has been recognized for centuries. However, statistical confirmation of pathogen spread by shipping is usually impractical. We present evidence of invasive spread of infectious salmon anemia in the salmon far...
متن کاملFrom the viral perspective: infectious salmon anemia virus (ISAV) transcriptome during the infective process in Atlantic salmon (Salmo salar).
The infectious salmon anemia virus (ISAV) is a severe disease that mainly affects the Atlantic salmon (Salmo salar) aquaculture industry. Although several transcriptional studies have aimed to understand Salmon-ISAV interaction through the evaluation of host-gene transcription, none of them has focused their attention upon the viral transcriptional dynamics. For this purpose, RNA-Seq and RT-qPC...
متن کاملA stochastic model for infectious salmon anemia (ISA) in Atlantic salmon farming.
Infectious salmon anemia (ISA) is one of the main infectious diseases in Atlantic salmon farming with major economical implications. Despite the strong regulatory interventions, the ISA epidemic is not under control, worldwide. We study the data covering salmon farming in Norway from 2002 to 2005 and propose a stochastic space-time model for the transmission of the virus. We model seaway transm...
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