CyHV-3: the third cyprinid herpesvirus

Area of Science:

• Ichthyopathology
• Virology
• Aquaculture

Background:

• Common carp (Cyprinus carpio L.) are vital freshwater fish in Europe and Asia.
• Cyprinid herpesvirus-3 (CyHV-3) causes koi herpesvirus disease (KHVD), leading to high morbidity and mortality in carp.
• KHVD is a notifiable disease globally, impacting aquaculture due to high stocking densities.

Purpose of the Study:

• To provide a comprehensive overview of cyprinid herpesvirus-3 (CyHV-3) and koi herpesvirus disease (KHVD).
• To highlight the ecological and economic significance of common carp and the threat posed by KHVD.
• To summarize current knowledge on CyHV-3 characteristics, detection, and disease management.

Main Methods:

• Review of scientific literature on CyHV-3 and KHVD.
• Analysis of viral genome sequencing data (KHV-J, KHV-U, KHV-I).
• Summary of diagnostic methods (PCR, ELISA) and immunization strategies.

Main Results:

• CyHV-3 is a large DNA virus (295 kb genome) within the Alloherpesviridae family.
• The virus replicates in cell nuclei and has mature particles of 170-200 nm.
• Effective detection methods exist, but immunization strategies may lead to carrier fish.

Conclusions:

• KHVD remains a significant threat to common carp populations worldwide.
• There is currently no effective treatment for koi herpesvirus disease.
• Further research into prevention and treatment strategies is crucial for carp health and aquaculture sustainability.