2009—2012年中山市流行性感冒监测结果分析

目的对2009—2012年中山市流行性感冒（流感）监测结果进行分析，了解流感的流行趋势和病毒型别，为制定流感防控策略提供科学依据。方法收集中山市流感样病例（ILI）监测、病原学监测以及流感暴发疫情监测资料进行分析，将Iu就诊指数（ILI％=门、急诊Iu就诊人数／门、急诊就诊病例总数×100％）和流感病毒检出阳性率作为分析指标。结果2009年流感病毒较为活跃，出现2次ILI就诊高峰，第1次高峰由甲（A）型H3N2亚型所致，第2次高峰由新甲（A）型H1N1亚型所致；2009年甲流大流行之后，2010年流感流行的强度迅速降低，处于相对平稳状态，上半年以B型流感病毒为主，下半年以甲（A）型H3N2亚型为主；2011—2012年新甲（A）型H1N1亚型、B型流感病毒和甲（A）型H3N2亚型交替流行，ILI就诊高峰均发生在春夏季；对全市4个监测年度各周的ILI％和病原学监测阳性率进行秩相关检验（r=0．701，P〈0．01），结果呈正相关；全市报告流感暴发疫情11起，报告发病共计580例，平均罹患率为1．25％，主要发生在中小学校。结论4个监测年度的优势毒株亚型之间呈交替变化的趋势并有一定的规律，ILI流行强度与流感病毒活动趋势一致。

Analysis on influenza surveillance in Zhongshan city from 2009 to 2012

Objective To analyse the results of influenza surveillance in Zhongshan city from 2009 to 2012, to understand its epidemiological characteristics and virus type, and provide scientific evidence for developing influenza prevention and control strategy. Methods Influenza surveillance system in Zhongshan was consisted of influenza-like-illness （ILI） surveillance,etiological surveillance and outbreak monitoring surveillance,ILI% （ILI% =outpatient and emergency ILI visits/outpatient and emergency total visitsxl00%）and the positive rate of influenza virus were the main analysis indexes. Results Influenza was active in 2009, with two peaks of clinic visits for ILI, and the first peak was caused by influenza A（H3N2）, while the second one was caused by the new influenza A（H1N1）. After the influenza pandemic in 2009, the epidemic of influenza in 2010 declined rapidly and remained at a relatively stable state. Influenza B virus was the major strain in the first half of the year,while A （H3N2）was the major strain in the second half of the year.From 2011 to 2012, the new influenza A （H1N1）,influenza B virus and influenza A （H3N2） subtype were alternately as dominant strains,and every year the peaks of clinic visits for ILI occurred in spring and summer.Spearman correlation analysis indicated that ILI rate and positive rate of etiology monitoring was positively correlated （r=0.701 ,P〈0.O1）.From 2009 to 2012,a total of 11 outbreaks with 580 cases were reported,which mainly occurred in primary and middle schools and the average attack rate was 1.25%. Conclusion From 2009 to 2012, the predominant strains changed regularly.The ILI epidemic strength was correlated with the influenza virus activity.