Acronym NA
Category
Aquaculture
Title Overføring av IPN-virus fra stamfisk til avkom - Transmission of IPN virus from broodstock to offspring Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Øystein Evensen Coordinator email oystein.evensen@veths.no
Coordinator institution
NVH - Norwegian School of Veterinary Science (Norway)
Institutions involved
NA
Start year 2002 End year 2003 Funding (€) € NA Website https://www.fhf.no/prosjekter/prosjektbasen/552032/ Summary Vertical infection of VPN virus, i.e. infection from parent fish (broodstock) to offspring (fry) detected for brook trout and rainbow trout without the mechanism being removed. Without reliable knowledge of such a transfer of Atlantic salmon, there have not been good enough arguments for, among other things, investing in effective broodstock control in salmon farming in Norway. It is not known what significance this had for the spread of infectious pancreatic necrosis virus (VPN virus) in Norwegian fish farming. Salmon fish can be covertly infected with the VPN virus, either as survivors of an IPN outbreak or of a subclinical infection. A covert infection with VPN virus can be difficult or impossible to detect. Until recently, cell culture has been considered the most effective method of identifying such an infection. Studies with reverse transcriptase and polymerase chain reaction (RT-PCR) have for some time been considered promising in terms of increased sensitivity so that a larger proportion of infected fish can be detected by RT-PCR than by cultivation. In a pilot study that formed the basis of the present project, 38 broodstock were examined for VPN virus in the year 2000. The virus was then detected by traditional culture in cell culture, from samples of 8 of 38 salmon (21%) and by means of RT- PCR, in 25 of 38 laks (66%). The RT-PCR examinations of the remaining samples gave uncertain results. This year class had undergone a severe IPN outbreak in the seawater phase. We assessed that the IPN outbreak in the seawater phase could be a possible reason why such a large proportion of the broodstock was infected with the IPN virus. The new project was designed based on a hypothesis that in another age group we would find a mixture of both virus-positive and virus-negative broodstock. We wanted to compare the incidence of virus in offspring after crosses where both parents had tested positive, with the incidence in offspring after parents who had both tested negative. It was also important to reduce the possibility that the fry groups in the facility could be infected by other means than via the parent fish. Against this background, we also wanted to examine the intake habits of the fry department in order, if possible, to reveal whether the fry could have been infected horizontally via sources other than the parent fish vertically. The main objective of the project was to investigate whether there could be a connection between the occurrence of! PN virus in broodstock and the occurrence of VPN virus in offspring, which could indicate that the virus had been transmitted from parent fish to fry.
Keywords
Fish health;
Land-based aquaculture;
Disease;
Broodstocks;
Fish;
Salmon;
Marine Region
76
Not associated to marine areas
0
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