Cyprinid herpesvirus 3

Cyprinid herpesvirus 3 (also known as CyHV-3 or Koi herpesvirus) is a species of virus in the family Herpesviridae, order Herpesvirales. It is a highly contagious virus that primarily affects koi and common carp.

Overview

Cyprinid herpesvirus 3 was first identified in the late 1990s in the United States and has since been reported in many countries worldwide. The virus causes a highly infectious disease known as Koi herpesvirus disease (KHVD), which can result in significant mortality in affected populations of koi and carp.

Transmission

The virus is primarily transmitted through direct contact between infected and susceptible fish. It can also be spread indirectly through the water, on equipment, or by birds that have been in contact with infected fish. The virus can survive in the environment for a period of time, particularly in water at lower temperatures.

Symptoms

Infected fish may show a range of symptoms including lethargy, loss of appetite, and changes in behaviour. Physical signs can include gill necrosis, skin lesions, and inflammation of the internal organs. However, some infected fish may not show any obvious signs of disease.

Diagnosis and Treatment

Diagnosis of Cyprinid herpesvirus 3 is typically based on clinical signs and confirmed by laboratory testing. There is currently no effective treatment for the virus. Management strategies focus on preventing the spread of the virus and include good biosecurity practices, quarantine of new fish, and regular monitoring of fish health.

Impact

The impact of Cyprinid herpesvirus 3 can be significant, particularly in commercial koi and carp farming where outbreaks can result in high mortality and economic loss. The virus can also have a negative impact on wild carp populations.

See Also

• Herpesviridae
• Koi
• Carp