Real-time PCR for the detection and quantitative analysis of IHNV in salmonids

The rapid identification and quantification of virus in diseased fish is a goal both conservationists and commercial aquaculturists have struggled to attain. Recently a technique for the detection of viral mRNA particles that uses fluorescent tagging and amplification has been developed. Utilizing p rimers and fluorescent labelled probes generated for the specific identific ation of the nucleocapsid (N) and glycoprotein (G) genes of infectious haem atopoietic necrosis virus (IHNV), and an instrument that measures cyclic em ittance of fluorescence, the presence or absence of virus can be easily and rapidly confirmed. This method is not only useful in confirming viral pres ence but is effective in measuring the relative or absolute quantity of vir us present within the sample. This allows for the determination of the heal th status of a carrier fish by measuring the quantity of viral genomes or t ranscribed viral genes present. Because this method is based on sequence de tection, instead of virus isolation in cell culture, it is also effective i n determining the presence of pathogenic organisms from water, fish feeds, or other potential reservoirs of infection.