Occurrence and prevention on virus diseases in common carp: A review

Common carp(Cyprinus carpio L.) is an important economic fish species in China.With the gradual increase of breeding range and density in aquaculture, the aquaculture ecosystems are being damaged to varying degrees, the diseases frequently break out in common carp.Among them, the influence range caused by viral diseases is the most extensive, and the mortality is the highest.It has become a bottleneck problem restricting the sustainable and healthy development of carp breeding industry.In this paper, the pathogen biology, occurrence, epidemic characters and prevention and control strategies of viral diseases in common carp such as spring viraemia of carp(SVC), koi herpesvirus disease(KHVD), viral edema of carp disease(VEC) and carp pox disease(CPD) were summarized, and the future research trends of viral diseases were prospected.There are still many problems to be further studied, such as why KHV could infect a variety of Cyprinidae related fishes, but the fish only carried virus not becoming a disease-causing? Whether the water temperature is a key factor for virus infection? How can viruses escape immune surveillance and infect fish? Whether there are differences in the transmission of viruses at different stages of infection? Since lack of effective methods to control the carp viral diseases, strengthening quarantine and immune control remains the main means of preventing and controlling viral diseases of carp.Therefore, in the future, the researchers should continue to strengthen the research on the pathogenic mechanism and transmission pathway of the virus, develop a new oral vaccine carrier and transmission system, and develop drugs that can effectively treat viral diseases based on RNAi technology, in order to ensure the healthy and sustainable development of carp breeding industry in China.