RESEARCH - Research Summary

Animal Production Theme

Research Summary

Infectious Salmon Anemia (ISA) is a viral disease that has caused major problems for the salmon industry in the Bay of Fundy since it was first diagnosed in 1996. It also presents a threat to the British Columbia salmon industry since the virus has spread to most major salmon producing regions of the world in the last 18 years.

There are number of diagnostic tests available to identify infected fish,. However, multiple tests often give contradictory and confusing results. It is essential to know the ability of each of these tests to correctly identify infected fish (i.e. sensitivity of the test) and non-infected fish (I.e. specificity of the test). This project will carry out a thorough, structured evaluation of all tests currently in common use and evaluate a new promising diagnostic procedure.

Test currently used routinely include: virus isolation, reverse transcriptase polymerase chain reaction (RT-PCR) (a molecular test for identifying segments of the viral genetic material), and indirect fluorescent antibody test (IFAT) (a test in which the virus particles are stained with a dye which make them fluoresce when viewed under a fluorescent microscope). One new test to be evaluated is an indirect ELISA for detecting antibodies to ISA virus in exposed fish (i.e. a test which measures the fish’s response to the infection). These tests will be evaluated by submitting common samples taken from fish from several populations. Seven laboratories are participating and a total of 8 test will be carried out on each fish sampled.

The results of this research will have two major impacts on the salmon aquaculture industry. First, knowing what each test results specifically means will allow for the design of superior disease control programs. Second, knowing the operating characteristics of the test will greatly facilitate the conduct of epidemiologic research into ways of controlling ISA in aquaculture industry.

Network Investigators

Ian Dohoo, Dept. of Health Management, UPEI, Charlottetown, PE
Larry Hammell, Dept. of Health Management, UPEI, Charlottetown, PE
Henrik Stryhn, Dept. of Health Management, UPEI, Charlottetown, PE