综合指数法建立北京市诺如病毒急性胃肠炎流行水平分级标准

Establishment of grading thresholds for epidemic intensity of norovirus acute gastroenteritis in Beijing by synthetic index method

目的建立北京市诺如病毒急性胃肠炎流行水平分级标准,针对不同流行水平制定相应防控措施建议.方法利用北京市2014—2018年4个流行季诺如病毒急性胃肠炎病原学及聚集性疫情监测数据,采用综合指数法,对原始监测数据进行标准化处理,赋予不同权重,计算周综合指数并划分流行强度等级.结果 4个流行季共208个监测周的综合指数值范围为0.2~4.4,中位数为0.5.将诺如病毒急性胃肠炎流行水平分为5个等级,等级1~5强度递增.0.5为流行期与非流行期的划分阈值,0.8、1.5和3.5分别作为流行强度等级2~5的划分阈值.经专家研讨制定相应等级防控建议.结论本研究建立了北京市诺如病毒急性胃肠炎流行水平分级标准,并提出相应防控措施,为2018—2019年流行季的防控工作提供了依据.

Objective To establish the grading thresholds for epidemic intensity of norovirus acute gastroenteritis in Beijing, and to provide prevention and control strategies for different grades of the epidemics. Methods Based on the epidemiological and virological surveillance data related to norovirus acute gastroenteritis in the four epidemic seasons from 2014 to 2018, the synthetic index method was used in standardization of the raw data, assignment of weights, calculation of weekly synthetic indexes and in grading epidemic intensity. Results The synthetic index values of 208 monitoring weeks in the four epidemic periods ranged from 0.2 to 4.4 with a median value of 0.5. The epidemic intensities of norovirus acute gastroenteritis were classified into five grades, with the intensities increased from grade 1 to grade 5. Synthetic index value of 0.5 was the threshold to divide epidemic and non-epidemic periods, while the values of 0.8, 1.5 and 3.5 were used as the division thresholds for epidemic intensities of grade 2 to grade 5, respectively. The corresponding prevention and control measures were discussed and proposed by experts. Conclusions This study established the grading standard for epidemics of norovirus acute gastroenteritis in Beijing and proposed corresponding prevention and control measures, which provided a basis for the prevention and control of the disease in Beijing in the 2018-2019 epidemic season.