Viral Studies on Carp Disease in China - with a Special Reference to
Herpesvirus on Common Carp

Xu Pao and Min Kuanhong

Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences

ABSTRACT

The present paper mainly deals with the general situation of the viral diseases affected on the Chinese carps in a recent decade in China. The viral disease is highly characterized by the fast transmission, great mortality and being difficult to control which has caused a heavy loss on the aquaculture systems. The paper further and specifically introduces the general status of herpes virus on carps in China and preventive measures against the outbreak of the disease from the ecological point of view and the environmental issues.

Since 1980s, there have been a rapid development of aquaculture in China, the percentage is getting higher and higher in the position agricultural development and turning one of the four major core production activities (grain, meat fish and eggs). In 1998, the fish production in China was up to 38 million tons. However, the fish diseases, particularly the virus disease becomes more and more prominent, epidemic, which lead to a heavy loss in the aquaculture activities in the recent years. Due to a long-length of incubation period, complex characters and high infection, the fish suffers from a high mortality. Also due to the small size of the pathogenic virus and the copying characters, it has a strong resistance against the antibiotics, while the chemicals application often lead to the death of the host prior to that of the pathogens. Therefore the treatment of the virus diseases is encountered with a great difficulty.

The following is the general situation of the virus disease observed in aquaculture systems in China:
1. Virus and morphology
2. Examination and diagnosis of fish virus diseases
3. Prevention and control of the virus disease and preparation of the vaccination
4. Fish herpesvirus diseases
4.1 SVC is a secondary disease confirmed by OIE, NACA and FAO
4.2 Eel Virus Disease (Eel mouth disease)
4.3 Herpesvirus of turbot (Tarphops oligolepis)
5. Countermeasures against virus diseases
5.1 Improvement of the aquaculture environment with ecological approaches
5.2 Tight control of the pathogenic transmission
5.3 Micro-ecologies to control the outbreak of the diseases
5.4 Eradicating the enemies by protecting the farmed species
5.5 Use of growth promoters to hasten the growth rate of the fish
5.6 Appropriate use of chemicals for the disease
5.7 Development and application of fish vaccines