基于层次分析法的牡蛎养殖过程中副溶血弧菌风险评估模型建立和初步应用

Establishment and Application of Risk Assessment Model of Vibrio parahaemolyticus in Oyster Culture Course Through Analytic Hierarchy Processing

副溶血弧菌是一种重要食源性致病菌,牡蛎是其主要携带者之一。为了量化评估牡蛎养殖过程中副溶血弧菌感染的风险,采用德菲尔法、层次分析法和多指标综合体系评价法,将专家经验知识和现代数学方法结合,构建了由评估指标体系、风险因素权重、评分标准、综合评价函数等组成的牡蛎养殖过程中副溶血弧菌风险评估模型。其中,评估指标体系包括水质、养殖管理、健康状况等3个准则层和水温、盐度、pH、氨氮、亚硝酸盐、溶解氧、养殖模式、养殖密度、场址选择、日常管理、细菌感染、病毒感染、寄生虫感染等13个指标层风险因素;3个准则层风险因素权重值集合为W={0.5278,0.3325,0.1396},指标层风险因素中水温(0.2270)、盐度(0.1368)和养殖密度(0.1409)等权重值较高,为影响副溶血弧菌感染的主要风险因子;分别建立了定性和定量评估指标的评分标准。以广东阳江某牡蛎养殖场为例,运用多指标综合体系评价法对该模型进行验证,得出该牡蛎养殖场春季、夏季、秋季和冬季副溶血弧菌感染发生风险概率为分别0.2281、0.5833、0.2723和0.1347,评估结果与实际调查结果相符,说明该模型可用于牡蛎养殖中副溶血弧菌感染风险估算。

Vibrio parahaemolyticus （VP） is a pathogen that is the leading cause of shellfish-associated cases of bacterial food poisoning. V. parahaemolyticus, detectable in both human and fish, has higher densities in oyster and other filter-feeding shellfish than in human. Raw and undercooked oyster is one of the most important ways of V. parahaemolyticus infection, thus reducing the number of V. parah- aemolyticus in oysters is essential to the safety of consumers. To assessment the risk of V. parahaemolyticus outbreak during oysters culture, the risk assessment framework of V. parahaemolyticus was established by using expert experience knowledge and modern mathematics method, which consisted of risk evaluating index system, analytic hierarchy process （AHP）, and multiple objective comprehensive evaluation （MOCE）. It was confirmed that 3 primary risk factors （water quality, cultivation and physical condition） and 13 secondary risk factors （water temperature, salinity, pH, ammonia, nitrite, dissolved oxygen, breeding mode, density, site selection, daily management, bacteria, parasites, viruses） determined the risk caused by V. parahaemolyticus. Risk assessment model of V. parahaemolyticus during oyster culture was constructed by analytic hierarchy processing. The weights of 3 primary risk factors were 0. 5278, 0. 3325, and 0. 1396. The top three index weight were water temperature （0. 2270）, salinity （0. 1368） and stocking density （0. 1409）. The risk degree of V. parahaemolyticus was determined by appropriate threshold. Then, it was preliminarily validated by studying the case of one oyster farm in Yangjiang, Guangdong with methods of multiple objective comprehensive evaluation, the risk value of V. parahaemolyticus outbreak in spring, summer, autumn and winter, respectively, was 0. 2281, 0. 5833, 0. 2723 and 0. 1347, respectively. The model was able to assess the risk of V. parahaemolyticus in oyster farming.