Infectious hematopoietic necrosis virus (IHNV) is a highly contagious and pathogenic virus belonging to the Rhabdoviridae family. It primarily affects fish, particularly those belonging to the salmonid family, including trout and salmon. IHNV causes a severe infectious disease known as infectious hematopoietic necrosis (IHN), which can lead to significant economic losses in aquaculture and wild fish populations.
The virus primarily targets the hematopoietic tissues, including the kidney, liver, and spleen, causing necrosis and a noticeable reddening of these organs. It is primarily transmitted horizontally through direct contact between infected and susceptible fish, particularly during stressful conditions or overcrowded environments. Additionally, IHNV can be transmitted vertically, from infected females to their offspring, further contributing to its spread.
Common clinical signs of IHNV infection include lethargy, anorexia, darkened coloration, bloated abdomen, and ultimately, hemorrhagic necrosis leading to high mortality rates. Infected fish may also shed the virus into the water, facilitating further transmission and contamination.
Prevention and control strategies for IHNV include strict biosecurity measures to prevent the introduction of the virus to fish farms or natural habitats. Vaccination is recommended, especially for at-risk populations and broodstock. Prompt diagnosis and isolation of infected fish are crucial to limit the spread of the disease. Additionally, environmental management practices, such as reducing stocking densities and improving water quality, can help mitigate the risk of IHNV outbreaks.
