IMMNOGENETIC ANALYSIS OF SCHISTOSOMIASIS JAPONICA IN CHINA

在中国沿江，日本血吸虫病仍是地方病。我们一直在对江西几个目标村的人群治疗效果进行评估。我们观察到，在再感染的水平上有两种类型，耐药和敏感。我们这项研究的最终目标是弄清决定其易感性的宿主因素。朱溪村位于江西省星子县鄱阳湖北岸。传播主要发生在汛期，通常从5月中旬开始，一直持续到10月。社区的生活是以物质农业为基础的。渔业在这一地区也很重要。再感染研究于1995年3月至12月开始。在研究开始时，在大规模化疗之前，所有在家的村民都被要求提供一份粪便标本，并复制41.7 mg加藤厚片进行定量检测日本血吸虫虫卵。然后，在1995年12月，…的再感染率对这些受试者进行了更多的ND强度检查.同时，在大便检查的同时采集两次静脉血样本。南山是位于江西省新建县鄱阳湖中心的一个小岛特有村落。南山市1991~1994年感染率分别为30.4%、33.4%、20.7%、17.2%。农业和渔业是这个村子的主要收入来源。1997年2月，根据1990-1994年间Kato-Katz病例的5年记录，选择相对易感或抵抗再感染的人群进行了一项回顾性研究。对于朱溪来说，抵抗者在两次考试中都应该有不到100个蛋。对于南山地区，抗性在5年内不应出现任何阳性产蛋量。与耐药个体相比，正常人的HLA-DRB1等位基因频率较高(优势比=4.13，95%可信区间=1.31~13.0)和HLA-DRB1^&lt；**&gt；1201的频率(OR=3.80，95%CI=1.02~d14.2)。因此，这两个等位基因与再次感染的易感性有关。在Bonferroni校正后，这些关联并不显著，因此有必要增加受试者的数量来确认关联。我们计划扩大这一领域，并分析与免疫反应性相关的其他多态遗传基因座。较少

Along Yangzhe River in China, Schistosomiasis japonica is still endemic. we have been estimating the efficiency of the mass-therapy on the prevalence of several targeted villages in Jiangxi. We observed that there were two categories, resistant and susceptible, in the levels of re-infection. Our final goal of this study is to clarigy the host factors which determine their susceptiblity.Method. Zhuxi village is located on the northern shore of Poyang Lake in Xingzi County, Jiangxi Province. Transmission occurs mainly during the flood season which usually begins in mid-May and goes through October. The life of the community is based on substance agriculture. Fishing is also important in this area. The reinfection study began from March to December 1995. In the beginning of study, before mass chemotherapy, all villagers at home were asked to give a stool specimen and duplicate 41.7mg Kato thick smears were examined quantitatively for S.japonicum eggs. Then, in Dec.1995, reinfection rate a … More nd intensity were examined for those subjects. Meanwhile, venous blood samples were collected twice at the same time as stool examinations. Nanshan is an islet endemic village, which located in the center of Poyang Lake, of Xinjian county, Jiangxi Province. The infection rate of Nanshan from 1991 to 1994 were 30.4%, 33.4%, 20.7%, 17.2% resoectively. Agriculture and fishing are the main income of this village. In February 1997, a retrospective study was designed to select subjects who are relative susceptible or resistant to reinfection based on a five-year Kato-Katz records (1990-1994).Results We have categorized two groups in the subjects in Zhuxi and Nanshan by using egg count record. For Zhuxi, the resistant should have less than 100 eggs in both exams. For Nanshan, the resistant should not have any positive egg count during 5 years period. Then we have typed them for their HLA-DRB1 alleles as shown in Table 1. Compared with the resistant individuals, normal people had higher frequency of HLA-DRB1^<**>0301 (Odds Ratio=4.13,95% Confidence Interval =1.31-13.0) and HLA-DRB1^<**>1201 (OR=3.80,95%CI=1.02-d14.2). Therefor, those two allels are associated with susceptibility to re-infection. Those associations are not significant after the Bonferroni correction, so it would be necesary to increase the number of the subjects to confirm the association. We are planning to expand the field and to analyze other polymorphic genetic loci that relate the immune responsiveness. Less