IMMNOGENETIC ANALYSIS OF SCHISTOSOMIASIS JAPONICA IN CHINA

在中国的长江沿岸，日本血吸虫病仍是一种地方性疾病。我们一直在对江西几个目标村庄的患病率进行群体治疗的效率评估。我们观察到，在再感染水平上有两类，耐药和易感。我们这项研究的最终目的是阐明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。渔业在这个地区也很重要。再感染研究开始于1995年3月至12月。在研究开始时，在集体化疗前，要求所有村民在家中提供粪便标本，并定量检查重复41.7mg加藤厚涂片是否有日本血吸虫卵。1995年12月，分别测定再感染率、再感染率、再感染率和再感染率。同时在粪便检查的同时采集2次静脉血。南山是江西省新建县鄱阳湖中心的一个海岛特有村。南山区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庄的主要收入来源。1997年2月，设计了一项回顾性研究，根据五年的Kato-Katz记录（1990-1994）选择对再感染相对易感或耐药的受试者。结果根据卵数记录将朱溪和南山地区的被试分为两组。对于朱溪来说，在两次测试中，抗性鸡蛋应该少于100个。对于南山，5年内应无阳性卵数。然后我们对他们的HLA-DRB1等位基因进行分型，如表1所示。与耐药个体相比，正常人HLA-DRB1^<**>0301（优势比=4.13,95%可信区间=1.31-13.0）和HLA-DRB1^<**>1201的频率更高（OR=3.80,95% ci =1.02-d14.2）。因此，这两个等位基因与再感染易感性有关。经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证实这种关联。我们正计划扩大这一领域，并分析与免疫反应有关的其他多态性基因位点。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