Infectious hematopoietic necrosis virus (IHNV; n = 18) was identified in the Korean national surveillance program between February 2013 and April 2015, suggesting that IHNV is a major viral pathogen in cultured salmonids. By phylogeny analysis, we found that the JRt-Nagano and JRt-Shizuoka groups could each be further subdivided into three distinct subtypes. The Korean strains were genetically similar to Japanese isolates, suggesting introduction from Japan. Interestingly, the amino acid sequences of the middle glycoprotein gene show that distinct Korean subtypes have circulated, indicating that the settled IHNVs might be evolved stably in cultured salmonid farm environments.
Keywords: Infectious hematopoietic necrosis virus; Korea; Salmonid; Surveillance.