Development of a Rapid Low-Cost Fecal-based TB Diagnostic for Children

项目摘要 结核病在全球范围内造成的死亡人数比任何其他传染病都多，然而在过去，结核病的影响 结核病对儿童的影响往往被忽视或最小化。年结核病(TB)诊断和报告不力 婴儿和儿童继续妨碍对儿童结核病负担和全世界结核病负担的准确估计。 儿童中结核病的发病率仍然很高。儿童结核病的诊断目前是具有挑战性的，因为 缺乏灵敏的看护点诊断测试，难以获得和使用可用的测试，以及 获取儿童结核病患者的痰标本。此外，可用的临床测试需要足够的 测试过程的基础设施支持，如稳定的电源、训练有素的人员或实验室设施 这排除了它们在外围设备中的使用。对于低资源国家来说，许多成本也令人望而却步 结核病负荷很高。目前，对儿童和儿童的低成本快速非痰结核病诊断的需求很大。 更容易获得的样本，只需最低限度的初级卫生保健技能即可获得，用于 对于儿童结核病的诊断，替代诊断将是非常可取的。当孩子咳嗽的时候，他们 通常会吞咽痰。已经表明，粪便，吞咽痰的最终目的地，是 这可能是检测儿童结核病的有用样本。事实上，活体结核分枝杆菌(Mtb) 已通过培养研究证明存在于粪便样本中。最近，有一些数字 尝试将GeneXpert®测试应用于儿童排泄物的尝试。而粪便样本的分析则是通过 GeneXpert®可能代表着一种新的儿科结核病诊断测试，它在外围设备中的使用非常严重 有限的。为了解决这个问题，我们设计并测试了一种基于痰的快速、低成本诊断(REFtb)。 用于可修改为用作儿科粪便测试的外周设置。建议的总体目标是 这项应用的研究是将这种以痰为基础的检测应用于以粪便为基础的儿科测试。基于 初步数据，我们相信，通过最小限度的优化，痰REFtb检测可以很容易地从 痰到粪便物质作为诊断试验。这些研究将集中在调整以痰为基础的试剂 在儿科粪便化验中使用，并在儿科粪便材料中测试粪便化验。我们计划 检查儿童非结核排泄物对REFtb试验的干扰活性，并测试已知的抑制剂 对痰为基础的REFtb检测进行优化，以便为基于粪便的检测开发优化的试剂组合。更长 我们计划继续开发货架稳定的儿科测试，并测试货架稳定的诊断 在初步临床试验中。这项拟议研究的完成将导致开发一种以粪便为基础的 适合低资源外围设备的儿科结核病诊断。这种以粪便为基础的儿科REFtb系统 克服目前限制结核病早期发现的经济和地理障碍，使患有结核病的儿童 目前，未确诊的患者现在可以低成本、快速地进行诊断。

Project Summary Tuberculosis (TB) causes more deaths worldwide than any other infectious disease, yet in the past, the impact of TB on children has been often dismissed or minimized. Poor diagnosis and reporting of tuberculosis (TB) in infants and children continue to hinder accurate estimates of the TB burden in children and the worldwide burden of tuberculosis remains high among children. The diagnosis of TB in children is challenging at present due to a lack of a sensitive point-of-care diagnostic tests, low access to and use of available tests, and difficulties of obtaining sputum specimens from children with TB. Moreover, available clinical tests need sufficient infrastructure support for the testing process such as a stable power supply, trained personnel, or lab facilities which preclude their use in peripheral settings. Many are also cost prohibitive for low resource countries where TB load is high. Currently, there is a great need for low cost rapid non-sputum TB diagnostics for children and a more accessible sample that can be obtained with minimal skill at primary health care level for use in an alternative diagnostic would be highly desirable for the diagnosis of TB in children. When children cough, they usually swallow the sputum. It has been shown that feces, the ultimate destination of swallowed sputum, is potentially a useful specimen for detection of TB in children. Indeed, viable Mycobacterium tuberculosis (Mtb) has been shown to be present in fecal samples using culture studies. More recently, there has been a number of attempts to adapt the GeneXpert® test to feces from children. While the analysis of stool specimens by GeneXpert® potentially represents a new diagnostic test for pediatric TB, its use in peripheral settings is severely limited. To solve this problem, we have designed and tested a rapid, low cost sputum-based diagnostic (REFtb) for peripheral settings that could be modified for use as a pediatric fecal test. The broad objective of the proposed research in this application is to adapt this sputum-based test to a fecal-based pediatric test. Based on preliminary data, we believe that with minimal optimization the sputum REFtb assay can easily be adapted from sputum to fecal matter as a diagnostic test. These studies will focus on adapting the sputum-based regents for use in a pediatric fecal-based assay and testing the fecal-based assay in pediatric fecal material. We plan to examine nonTB fecal material from children for interference activities to the REFtb test and test known inhibitors of the sputum-based REFtb test in order to develop an optimized reagent mix for the fecal-based test. Longer term we plan to continue development to develop a shelf-stable pediatric test and test the shelf-stable diagnostic in preliminary clinical trials. Completion of this proposed research will result in the development of a fecal-based pediatric TB diagnostic suitable for low resource peripheral settings. This fecal-based pediatric REFtb system overcomes the financial and geographical barriers that currently limit early TB detection so children with TB that currently go undiagnosed can now be diagnosed in a low-cost and rapid manner.