2010-2014年湖州市流感病毒流行特征分析

Epidemiological characteristics of the influenza virus in Huzhou from 2010-2014

目的分析湖州市流行性感冒病毒型别分布,阐述流行特征,为制定预防控制措施提供依据。方法湖州市两家流感哨点监测医院按天登记收集流感样病例(ILI)监测数据,网络实验室对ILI标本进行核酸检测。整理湖州市2010-2014年ILI监测和病原学检测结果进行综合分析。结果 2010-2014年,湖州市共核酸检测流感样病例标本6 917份,阳性1 305份,阳性率为18.87%;其中乙型占44.37%、季H3型占41.23%、新甲H1型占14.18%、混合感染占0.22%、无季H1型检出。每年都存在冬春季流行高峰,2010年、2012年和2014年存在夏秋季次高峰。各年份间(χ2=172.33,P<0.05)、各年龄组间(χ2=145.05,P<0.05)阳性率差异存在统计学意义,男女间(χ2=3.94,P=0.05)阳性率差异无统计学意义。结论湖州市流感病毒流行具有明显的季节性,最高峰为冬春季、次高峰为夏秋季;存在甲型和乙型流感病毒交替转换流行的现象,且病毒型别转换后都会引起一波流行高峰,季H1型可能已经被新甲H1型所取代。建议在流行期和病毒型别转换期重点做好监测、预警和防控工作,并对人群感染情况和夏秋季次高峰形成原因进行进一步的研究分析。

Objective To analyze the epidemiological characteristics and distribution of virus subtypes of influenza in the City of Huzhou in order to provide a scientific basis for the prevention and control of influenza. Methods Data on moni- toring of influenza-like illness （ILI） from 2010--2014 and specimens from two influenza sentinel surveillance hospitals in the City of Huzhou were collected. Nucleic acids in specimens of ILI were detected by an associated influenza laboratory. A comprehensive analysis was performed to investigate the ILI data and the results of pathogen detection. Results From 2010--2014, a total of 6 917 specimens of ILl were obtained and pathogens in those specimens were detected. Of those specimens, 1 305 （18.87%） tested positive for nucleic acids of the influenza virus. Subtype B strains were found in 44.37% of the specimens, seasonal H3 was found in 41.23%, A （HINI） pdm09 was found in 14. 18%, and a mixed subtype was found in 0.22% seasonal H1 was not detected. The incidence of influenza peaked in the winter and spring. A smaller peak in incidence occurred in the summer and autumn of 2010, 2012, and 2014. There were statistically signifi- cant differences in positivity for ILI by year （χ2= 172.33, P〈0.05） and by age group （χ2 = 145.05, P〈0.05）, and there were no statistically significant differences by gender （χ2 =3.94, P=0.05）. Conclusion The incidence of influenza in the City of Huzhou has obvious seasonality. The incidence of influenza peaks in the winter and spring. A smaller peak in incidence occurs in the summer and autumn. Outbreaks of influenza appear to alternate between subtype A and B by year. This alternation in virus subtypes will cause an outbreak of influenza. The seasonal H1 subtype may have been replaced by A （H1N1） pdm09. During an influenza outbreak and alternation in the virus subtype, more attention should be paid to surveillance, early warning, prevention, and control. Further research should be conducted to determine the state of infection in the human population and to determine the causes of smaller peaks in the incidence of influenza in the summer and autumn.