isolation and identification of infectious hematopoietic necrosis virus (ihnv) from farmed rainbow trout (oncorhynchus mykiss) in kohgiluyeh and boyer-ahmad province

Over time, the global consumption of aquatic animal foods has grown at a faster annual rate than the global population, and the stagnation or decline of marine and freshwater catches poses challenges for food security in many low-income nations. one viable way to close this gap in the market for aquatic food is through aquaculture. aquaculture has increased the availability of aquatic animal foods, often at lower costs, to areas and nations that would otherwise not have access to capture fishery production and improve food security and nutrition. iran produces 417,000 metric tons of freshwater fish, ranking as the 10th largest producer globally in this sector, and is one of the world’s leading producers of rainbow trout (oncorhynchus mykiss). infectious diseases inflict economic losses on the industry and threaten consumer health؛ therefore, the diagnosis of disease incidence in advance has become increasingly apparent. infectious hematopoietic necrosis virus (ihnv) is the etiological agent of contagious diseases (ihn), mainly in salmonid fish. in this study, we isolated and identified ihnv in rainbow trout fingerlings from yasuj city, kohgiluyeh and boyer-ahmad province, iran. the affected fish suffered from exophthalmia, lethargy, darkened body coloration, and petechial hemorrhages in the muscles. ten moribund fish, weighing 50 g, were collected and transferred to a diagnostic laboratory. the kidney and spleen of fish were extracted and homogenized tissues were inoculated in the epc cell line and incubated for two weeks. after observing cytopathic effects, rna was extracted from cpe positive samples to prepare cdna, and a reverse transcription polymerase chain reaction (rt-pcr) assay targeting the ihnv glycoprotein (g) gene was used to detect the ihn virus. upon confirmation of virus isolation, the farm manager was advised to implement appropriate health management practices.