SVC kits criticised in study


Some testing kits sold for the detection of SVC fail to accurately detect the presence of the virus.

Scientists working at The Centre for Environment Fisheries and Aquaculture Science (CEFAS) in Weymouth undertook a study of two test kits for detecting of the deadly virus Spring Viraemia of Carp and found that both gave results that could have given misleading results.

Their study, which is due to be published in the journal Diseases of Aquatic Organisms, looked at an Enzyme-Linked Immunosorbent Assay (ELISA) kit which used a polyclonal antiserum from rabbits, and an Indirect Flourescent Antibody Test (IFAT), which uses a monoclonal antibody from mice, and tested them with a selection of four different types of SVC virus.

The test viruses were all fish rhabdoviruses and came from four recently described genogroups: Geogroup I (the SVC virus); Genogroup II (Grass carp rhabdovirus); Genogroup III (Pike fry rhabdovirus) and Genogroup IV (Tench rhabdovirus).

The results suggest that the ELISA-based test kit was non-specific and could not tell the difference between SVC and any of the isolates from Geogroups II, III or IV.

The IFAT kit detected SVC, but it was too specific and only managed to spot one of the four SVC isolates used to test the kit.

Dixon and Longshaw, who undertook the work, say that reliance on these kits alone could lead to misidentification.

Spring Viraemia of Carp is a notifiable disease in the UK.

For more details see the paper: Dixon PF and CB Longshaw (2005) - Assessment of commercial test kits for identification of spring viraemia of carp virus. Diseases of Aquatic Organisms. 2005. Nov. 9;67(1-2):25-9.