2012～2014年中国西藏自治区5岁以下健康儿童肠道病毒携带状况分析

Analysis of Enterovirus Carrying Status in Healthy Children under 5 Years Old in Tibet Autonomous Region from 2012 to 2014,China

了解西藏自治区2012~2014年5岁以下健康儿童粪便标本中携带肠道病毒的血清型分布及流行特点。采集西藏自治区三地(拉萨、日喀则和山南地区)5岁以下健康儿童的粪便标本,同时收集相关流行病学信息。使用RD和L20B细胞进行病毒分离,将阳性分离株用肠道病毒分子定型法进行血清型鉴定。2012~2014年从西藏自治区5岁以下健康儿童中共采集了460份粪便标本(每名儿童采集1份),分离到肠道病毒共133株,包括脊髓灰质炎(脊灰)疫苗株33株,肠道病毒分离率为28.91%,非脊灰肠道病毒的分离率为21.74%。西藏自治区健康人群肠道病毒携带率和携带病毒的型别存在年代和地域的差异,但均以EV-B为主。其中在2012~2014年中,每年非脊灰肠道病毒谱中CV-B3是分离数量最多的。2012~2014年西藏5岁以下健康儿童中没有检出脊灰野病毒和脊灰疫苗衍生病毒,维持了无脊灰状态。检出了多种非脊灰肠道病毒,CV-B3一直在西藏自治区尤其是拉萨市健康儿童中隐性传播。本研究不仅为我国维持无脊灰工作提供坚实的实验室依据,同时,对非脊灰肠道病毒的流行本底的研究,为西藏自治区非脊灰肠道病毒的暴发提供预测预警信息和科技支撑。

To investigate the serotype distribution and epidemic characteristics of enteroviruses in stool specimens from healthy children under 5 years old in Tibet autonomous region during 2012-2014. Stool specimens of healthy children under 5 years old from three cities of Tibet autonomous region （Lhasa, Shigatse and Shannan） were collected,and relevant epidemiological information was collect together with the samples. Viral isolation was performed by inoculating the samples onto the RD and L20 cells, molecular typing method was used to identify the enterovirus serotype of the positive enteroviral isolates. 460 stool samples were collected from 460 healthy children under 5 years old in Tibet autonomous region during 2012 to 2014, and total 133 enteroviral isolated were obtained including 33 vaccine-related polioviruses, the total enteroviral isolation rate is 28.91%, and non-polio enteroviral isolation rate is 21.74%. There have differ- ences in time and geographic distribution of the enteroviral carrying rate and kinds of the serotypes among the healthy children under 5 years old in Tibet autonomous region, however, enterovirus species B （CV-B） is the predominant. Among them, CV-B3 has the largest number of non-polio enteroviruses isolated in each of the year. There is no wild polioviruses and vaccine-derived polioviruses detected in the stool samples collected from the healthy children under 5 years old in Tibet autonomous region during 2012-2014, ＂polio free status＂ is maintenance. Multiple serotypes of enteroviruses were detected; successive hidden transmission of CV-B3 was identified in the healthy children under 5 years old in Tibet autonomous region, especially in Lasha City. This study not only provides a solid laboratory data for the maintenance of ＂polio free status＂ in China, but also provides forecasting and early warning information and scientific and tech- nological support for disease control of the enterovirus-related disease outbreaks, based on the research of the epidemic baseline of enteroviruses in Tibet Autonomous Region.