2017年广东省秋季手足口病疫情高发流行特征及因素分析

摘要

目的 探索广东省2017年秋季手足口病疫情异常升高的原因,为疫情防控提供参考依据.方法 通过“中国疾病预防控制信息系统”收集广东省手足口病个案信息、暴发疫情信息和人口学信息.收集广东省手足口病监测哨点每周送检的病例粪便或肛拭子标本,采用实时反转录聚合酶链反应或反转录聚合酶链反应技术对监测样本进行肠道病毒核酸检测.选取2016-2017年柯萨奇病毒A组6型(Cox A6)核酸阳性标本进行VP1全长序列测序并进行基因进化分析.采用Excel软件进行数据录入,使用SPSS 16.0软件进行统计学分析.结果 2017年9月1日至10月31日,广东省报告手足口病152 791例,较2011-2016年同期平均水平增加133.25％,较2017年夏季流行高峰期增加23.16％.秋季发病峰值(24 822例/周)较2017年夏季高峰峰值升高34.72％,较2011-2016年同期平均水平升高167.71％.发病强度(以周均发病率计算)除湛江市外,20个地市均有不同程度增加,云浮、茂名等9个地市增幅超过100.00％.各年龄组发病率分布均高于2013-2016年同期平均水平,病例职业构成均以散居儿童为主.9-10月哨点监测Cox A6阳性率超过80％.2017年,Cox A6病毒核苷酸同源性为97.3％,而与2015年和2016年毒株同源性逐年降低.结论 2017年秋季广东省手足口病出现异常大幅增加,疫情高发由全省整体发病水平增长引起,与优势毒株转为Cox A6有关.%Objective To understand the factors associated with the abnormal increase of hand,food and mouth disease (HFMD) cases in autumn of 2017 in Guangdong province and provide scientific evidence for HFMD prevention and control.Methods The information about HFMD cases and outbreaks were collected through National Disease Reporting Information System.The stool samples and anal swab samples were collected weekly from HFMD sentinel hospitals in Guangdong for real time RT-PCR or RT-PCR to detect enterovirus nucleic acid.The positive samples of Cox A6 nucleic acid were selected for full length sequence amplification to find out the amino acid changes of gene loci.Microsoft Office Excel was used for data entry and SPSS16.0 was used for statistical analysis.Results A total of 152 791 HFMD cases were reported from 1 September to 31 October in 2017,an increase of 133.25％ compared with the same period during 2011-2016 and an increase of 23.16％ compared with summer in 2017.During the incidence peak in this autumn,24 822 cases occurred per week,an increase of 34.72％ compared with summer peak in 2017 and an increase of 167.71％ compared with the incidence peaks during the same period from 2011 to 2016.The incidence intensity (calculated according to weekly incidence) increased in 20 prefectures except Zhanjiang and the increases of 100.00％ were observed in 9 prefectures,including Yunfu and Maoming.The incidences in all age groups were higher than those during the same period from 2013 to 2016.Most cases were children outside child care settings.The sentinel surveillance indicated that the positive rate of Cox A6 from September to October was ＞ 80％.The nucleotide homology of Cox A6 virus in 2017 was 97.3％,which reduced comparing with the result of 2015 and 2016.Conclusion There was an abnormal growth of HFMD incidence in Guangdong in autumn of 2017.This study indicated that the high incidence was associated with the predominant strain shift to Cox A6,resulting in overall increase of HFMD incidence in Guangdong.