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Universal reverse-transcriptase real-time PCR for infectious hematopoietic necrosis virus (IHNV)

December 9, 2013

Infectious hematopoietic necrosis virus (IHNV) is an acute pathogen of salmonid fishes in North America, Europe and Asia and is reportable to the World Organization for Animal Health (OIE). Phylogenetic analysis has identified 5 major virus genogroups of IHNV worldwide, designated U, M, L, E and J; multiple subtypes also exist within those genogroups. Here, we report the development and validation of a universal IHNV reverse-transcriptase real-time PCR (RT-rPCR) assay targeting the IHNV nucleocapsid (N) gene. Properties of diagnostic sensitivity (DSe) and specificity (DSp) were defined using laboratory-challenged steelhead trout Oncorhynchus mykiss, and the new assay was compared to the OIE-accepted conventional PCR test and virus isolation in cell culture. The IHNV N gene RT-rPCR had 100% DSp and DSe and a higher estimated diagnostic odds ratio (DOR) than virus culture or conventional PCR. The RT-rPCR assay was highly repeatable within a laboratory and highly reproducible between laboratories. Field testing of the assay was conducted on a random sample of juvenile steelhead collected from a hatchery raceway experiencing an IHN epizootic. The RT-rPCR detected a greater number of positive samples than cell culture and there was 40% agreement between the 2 tests. Overall, the RT-rPCR assay was highly sensitive, specific, repeatable and reproducible and is suitable for use in a diagnostic setting.

Citation Information

Publication Year 2013
Title Universal reverse-transcriptase real-time PCR for infectious hematopoietic necrosis virus (IHNV)
DOI 10.3354/dao02644
Authors Maureen K. Purcell, Rachel L. Thompson, Kyle A. Garver, Laura M. Hawley, William N. Batts, Laura Sprague, Corie Sampson, James R. Winton
Publication Type Article
Publication Subtype Journal Article
Series Title Diseases of Aquatic Organisms
Index ID 70058654
Record Source USGS Publications Warehouse
USGS Organization Western Fisheries Research Center