石斑鱼虹彩病毒病发生风险评估模型的建立和验证

为评估石斑鱼养殖过程虹彩病毒病发生的风险,实验结合Delphi法和层次分析法(analytic hierarchy process, AHP)构建新加坡石斑鱼虹彩病毒(SGIV)发生的风险评估模型。风险因素评估指标体系包括1个目标层(石斑鱼虹彩病毒病发生风险),5个准则层(水质、石斑鱼健康状况、饲养管理、养殖模式和养殖环境)和20个指标层风险因素(水温、pH、溶解氧、氨氮、病毒感染、细菌感染等)。准则层风险因素权重值集合为W={0.129 8,0.367 2,0.173 3,0.032 7,0.297 1},指标层风险因素中病毒感染(0.248 5)、邻近区域发病情况(0.138 4)、水温(0.112 3)和养殖密度(0.105 0)等权重值较高,推测它们是影响石斑鱼虹彩病毒病暴发的高风险因素。进一步实验室模拟感染实验结果表明,养殖密度、病毒感染剂量及养殖温度均显著影响鱼体内新加坡石斑鱼虹彩病毒(SGIV)的复制及实验鱼死亡率。上述结论和评估模型中推定的高风险因素相吻合,说明该模型可用于石斑鱼养殖过程中虹彩病毒病发生的风险评估。

Establishment and verification of a risk assessment model for grouper Iridovirus disease in grouper, Epinephelus sp.

Singapore grouper iridovirus (SGIV), one of the most important viral pathogens in grouper, has caused great economic losses to grouper industry. To evaluate the risk of iridovirus disease in grouper aquaculture, a risk assessment model of grouper iridovirus disease was established using Delphi method and Analytic Hierarchy Process (AHP) method in this study. The evaluation index system consisted of 1 target level (risk of grouper iridovirus disease), 5 criterion layers (including water quality, grouper health status, feeding management, aquaculture mode and aquaculture environment), and 20 risk factors at the index level (including water temperature, pH, dissolved oxygen, ammonia nitrogen, iridovirus infection, bacterial infection etc.). The weight values of 5 criterion-level risk factors was W= {0.1298, 0.3672, 0.1733, 0.0327, 0.2971}. The higher wight values of risk factors, including virus infection, incidence in neighboring areas, water temperature, aquaculture density were 0.2485, 0.1384, 0.1123 and 0.1050, respectively, suggested that these factors might be crucial for the incidence of grouper iridovirus disease in aquaculture. Consistently, the infection experiments in laboratory confirmed that virus dose, density, and temperature all significantly affected the virus replication and the mortality of the fish. Thus, it was proposed that our risk assessment model could be used to assess the risk of iridovirus disease during grouper aquaculture.