1999-2005年我国婴幼儿人杯状病毒腹泻研究

Investigation of Human Calicivirus(HuCV) Diarrhea among Infantile and Young Children in China,1999-2005

人杯状病毒(HuCV)是世界范围内急性腹泻的重要病原。此文收集我国长春、北京、河北卢龙、兰州、昆明等13个地区1999-2005年5岁以下腹泻患儿检测轮状病毒为阴性的粪便标本4426份,用ELISA和RT-PCR方法检测HuCV,结果表明HuCV检测阳性率为19%(8.3%-38.6%)。对其中151株HuCV PCR产物测序进行核苷酸序列比对构建的系统发生树表明,我国流行的HuCV以诺如病毒(NV)为主(146/151,占96.7%),其中绝大多数为GGⅡ/4基因型(99/146),其它依次为GGⅡ/3(22/146)、GGⅡ/5(8/146)、GGⅡ/6(2/146)、GGⅡ/7(2/146)、GGⅡ/8(2/146)和GGⅠ/2(2/146),札如病毒(SV)共5株,均属SGⅡ。此外有9株NV GGⅡ遗传组毒株,尚不能归入现有基因型,可能为我国特有的新基因型,表明我国流行的HuCV毒株存在很高的遗传多样性。我国婴幼儿HuCV腹泻全年都有发生,但秋冬季(10月-次年1月)有一个发病高峰,病例以6-17月龄组最多,至3岁时超过96%的儿童都感染过HuCV。对我国流行的HuCV不同毒株的地区分布,不同年度HuCV检测阳性率的变化趋势进行了讨论。

Human calicivirus （HuCV） has been well known as an important pathogen of outbreak and sporadic acute nonbacterial gastroenteritis worldwide. To investigate epidemiological feature and genetic diversity of HuCV among children in China, fecal specimens were collected from children under 5 years of age with acute diarrhea at 13 hospitals in different provinces across China. The study was performed year-round from January 1999 to June 2005. Fecal specimens were tested for bacteria and rotavirus first and the negative specimens then were tested for HuCV using ELISA and RT-PCR. PCR amplicons were cloned and sequenced for strain characterization. A total of 4426 rotavirus -negative fecal samples were screened. From these, 840（19 % ） were positive for HuCV by either or both ELISA（ 14 % ） and RT-PCR（9.6 % ）. HuCV infection occurred year-round with an epi- demic in each winter（October-January） and mainly in children at 6 - 17 months of age. Of 151 HuCV strains characterized, 146 belong to norovirus（NV, 96.7 % ） and 5 were sapoviruses（SV）. Among norovirus strains, genotype GG Ⅱ/4 was most common （99/146）, followed by GG Ⅱ/3 （22/146）, GG Ⅱ/5 （8/146）, and 2 strains of each of GG Ⅱ/6, GG Ⅱ/7, GG Ⅱ/8, and GG Ⅰ/2, the other 9 strains of NV GG Ⅱ were unique, potentially belonging to new genotypes. These results plus the epidemiology data suggested that HuCVs are an important cause of severe diarrhea in Chinese children that were under reported due to a lack of a simple diagnostic assay. The finding of the potential new genotypes indicates that the current assays need to be improved for broader detection and besides, a continual surveillance for better understanding the epidemiology the disease burden and the searching for new strains of HuCVs is necessary.