2011-2012年度辽宁省流行性感冒监测分析

目的 了解2011-2012年度辽宁省流行性感冒(流感)的流行特征及流感流行优势毒株的分布,为预防控制流感提供参考依据。 方法 对2011-2012年度流感样病例(influenza-like illness,ILI)监测哨点医院的ILI和病原学监测结果进行流行病学分析。 结果 辽宁省2011-2012年度流感监测哨点医院ILI就诊百分比(ILI%)平均为3.34%, 较上年度有所下降,呈现冬春季流行高峰。全年共分离到流感毒株540株,总阳性率为6.38%,B型为流行株,病原学监测结果呈现多种流感病毒交替流行或混合流行的特点,分布有明显的季节性。流行株在流行后期发生了变化,由B(Yamagata)亚型流行株逐渐转为季节性H3N2型和B(Victoria)亚型。对ILI%与流感病毒分离率进行秩相关分析,相关系数为0.648(P结论 辽宁省流感流行呈现冬春季高峰,流行优势毒株随季节变化而出现差异,2012年的下半年辽宁省的流行株可能转变为H3N2型和B(Victoria)亚型。

Surveillance of influenza in Liaoning province, 2011-2012

Objective To understand epidemiological characteristics of influenza and the distribution of predominant virus strain in Liaoning province from 2011 to 2012, and provide evidence for the prevention and control of influenza. Methods Descriptive analysis was conducted on the incidence data of influenza like illness (ILI) and pathogen surveillance results from the influenza sentinel hospitals in Liaoning from 2011 to 2012. Results During this period, the proportion of ILI treated by hospitals was 3.34%, a slight decline compared with previous influenza season. The incidence peaks occurred in spring and winter. Totally 540 strains of influenza viruses were isolated, the isolation rate was 6.38%. Influenza B virus was predominant during the whole surveillance period. Etiological surveillance results revealed that multi type viruses circulated alternatively or co-circulated with obvious seasonality. Predominant strain changed at late phase of the influenza season from Influenza B virus/Yamagata lineage to seasonal influenza A (H3N2) virus or B virus/Victoria lineage. The ILI proportion was positively correlated with virus isolation rate (correlation coefficient: 0.648, PConclusion The incidence peaks of influenza were in spring and winter in Liaoning. The predominant strain varied with season and might be influenza A (H3N2) virus and B virus/Victoria lineage in the second half of 2012.