Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
National Institute for Medical Research, Mwanza, Tanzania.
Front Immunol. 2023 Sep 11;14:1216710. doi: 10.3389/fimmu.2023.1216710. eCollection 2023.
Among the challenges in schistosomiasis surveillance and mapping surveys is the lack of a sensitive diagnostic method especially in low transmission setting. Currently, the WHO recommends the use point-of-care circulating cathodic antigen (Schisto POC-CCA) tests for surveillance and mapping of intestinal schistosomiasis. However, Schisto POC-CCA test has its drawbacks, one of which is the timely availability of test kits. One approach to overcoming this challenge is to develop a low-cost sampling method that allows for the collection and transport of urine specimens even in resource-limited settings.
To develop a simple and efficient method for the collection and detection of () CCA using urine spotted onto filter paper.
To develop a dried urine spot (DUS) method, various dried matrix extraction parameters were tested and optimized using predesigned steps. The parameters include the size of filter paper (determined by the number of punches), volume of solvents, and type of solvent. Moreover, we optimized the incubation conditions (time and temperature). Urine and stool specimens to conduct the experiments were collected from volunteer fishermen in Mwanza and this project staff. Data were entered into the Microsoft Excel spreadsheet and IBM Statistical Package for the Social Sciences, version 20 for analysis.
The optimal results were obtained when the procedure was run under the following conditions: Five punches of filter paper containing DUS were dissolved in 150 µl of distilled water and incubated at room temperature for 24 hours in an Eppendorf tube. More than 93% of the assays performed under these conditions produced results that were either comparable to or significantly better than the standard method.
This study demonstrates the feasibility of collecting urine specimen (DUS) using filter paper and detecting CCA from DUS specimen using the Schisto POC-CCA cassette test.
在血吸虫病监测和绘图调查中存在挑战，特别是在低传播环境下缺乏敏感的诊断方法。目前，世界卫生组织建议使用即时检测循环阴极抗原（Schisto POC-CCA）检测方法进行肠道血吸虫病的监测和绘图。然而，Schisto POC-CCA 检测方法存在其缺点，其中之一是检测试剂盒的及时可用性。克服这一挑战的一种方法是开发一种低成本的采样方法，即使在资源有限的环境下，也可以采集和运输尿液标本。
开发一种简单高效的方法，使用尿液斑点采集滤纸收集和检测（）CCA。
为了开发一种干燥尿液斑点（DUS）方法，使用预设计的步骤测试和优化了各种干燥基质提取参数。这些参数包括滤纸的大小（由打孔数量决定）、溶剂的体积和溶剂的类型。此外，我们还优化了孵育条件（时间和温度）。用于进行实验的尿液和粪便标本来自姆万扎的志愿渔民和本项目工作人员。数据输入到 Microsoft Excel 电子表格和 IBM Statistical Package for the Social Sciences 版本 20 进行分析。
在以下条件下运行时，获得了最佳结果：将包含 DUS 的五张滤纸穿孔后溶解在 150 µl 蒸馏水中，并在 Eppendorf 管中于室温下孵育 24 小时。在这些条件下进行的超过 93%的检测都产生了与标准方法相当或显著更好的结果。
本研究证明了使用滤纸采集尿液标本（DUS）和使用 Schisto POC-CCA 检测盒检测 DUS 标本中的 CCA 的可行性。
