Basic and Operational Researches for The Global Elimination of Lymphatic Filariasis

我们开发了一种新的以尿液为样本的免疫诊断方法（尿液ELISA，灵敏度为96.5%，特异性为99.0%）。该方法在实地研究中得到了验证。尿液ELISA法测定感染强度尿液ELISA法的一大优点是易于应用于幼儿。它们是一个哨兵种群，可以表明新的丝虫病感染。（我们已经证实，从受感染母亲转移到新生儿的IgG4在一年内消失了。）在斯里兰卡的一个高流行区，IgG4阳性出现在1岁时，抗体滴度在3岁时达到高水平。在泰国低流行区，10岁左右出现阳性，20岁后呈高滴度。在韩国某丝虫病消失地区，40岁前无阳性。采用尿酶联免疫吸附试验（ELISA）对斯里兰卡Deniyaya地区学龄儿童进行大规模药物给药（MDA）前后血清丝虫病IgG的测定。治疗后，特异性IgG4的阳性率和滴度明显降低，提示尿液ELISA可用于监测MDA项目。此外，在确认丝虫病已被消除的2个中国村庄，接受elisa检测的1万多名学童全部呈阴性。根据当地居民提供的信息制作丝虫病分布图，向当地领导邮寄调查问卷，了解其所在村庄象皮病和鞘膜积液病例的存在情况和数量。这项研究揭示了许多有丝虫病病例的村庄，这些村庄以前从未报告过丝虫病。利用尿液ELISA进行的免疫流行病学研究显示，这些村庄可能存在丝虫病传播。利用重组蛋白开发新的诊断方法。重组SXP-1蛋白和几丁质内质酶蛋白成功用于该研究。前者似乎特别有希望。有1例以上象皮病病例的家庭遗传分析这项研究正在进行中，并积累了一些有趣的发现。少

We have developed a new immunodiagnostic method that uses urine as samples (urine ELISA with the sensitivity of 96.5% and the specificity of 99.0%). The method was tested for the usefulness in field studies.1.Urine ELISA for measuring the intensity of infectionA big advantage of urine ELISA is its ease in applying the method to young children. They are a sentinel population that can indicate new filarial infections. (We have confirmed that IgG4 transferred from infected mothers to their new born babies disappeared within a year.) In a high endemic area in Sri Lanka, the IgG4 positive appeared at age 1 year, and the antibody titers reached a high level by age 3. In a low endemic area in Thailand, the positive appeared at around 10 years, and showed a high titer level after 20 years of age. In a filariasis-disappeared area in Korea, there was no positive before 40 years of age.2.Urine ELISA for evaluating Mass Drug Administration (MDA), and confirming elimination of filariasisUrinary IgG … More 4 levels were studied with schoolchildren in Deniyaya area, Sri Lanka, before and after MDA. After treatment, the positive rate and titers of specific IgG4 reduced clearly, suggesting that urine ELISA is useful to monitor a MDA program. Also in 2 Chinese villages, where filariasis elimination had been confirmed, all of more than 10,000 schoolchildren examined were confirmed negative with the ELISA.3.Making a filariasis distribution map based on information given by local peopleQuestionnaires were mailed to local leaders, asking the presence and the number of elephantiasis and hydrocele cases in their villages. The study revealed many villages with the cases, where filariasis had not been reported before. Immunoepidemiological studies using urine ELISA showed a possible filariasis transmission in such villages.4.Development of new diagnostic methods using recombinant proteins.Recombinant SXP-1 and endochitinase proteins were used for this study successfully. The former seems to be particularly promising.5.Genetic analysis of families with more than 1 elephantiasis caseThis study is going on and some interesting findings are being accumulated. Less