Wahba Mina, Chitemo Heaven D, Misko Vyacheslav R, Kinabo Doris, Briet Matthieu, Vicca Jo, Levecke Bruno, Mazigo Humphrey D, De Malsche Wim
µFlow Group, Department of Bioengineering Sciences, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium.
SALTO Agro-Bio Research Group, Odisee, University of Applied Sciences, 9100 Sint-Niklaas, Belgium.
Micromachines (Basel). 2025 Jul 24;16(8):847. doi: 10.3390/mi16080847.
Soil-transmitted helminths (STHs) present a significant global health challenge, particularly in tropical and subtropical regions. The current diagnostic standard involves the microscopic examination of a stool smear but it lacks sensitivity to detect infections of low intensity. Innovative solutions like lab-on-a-disk (LoD) technologies are emerging, showing promise in detecting low-intensity infections. Field tests conducted using our SIMPAQ (single-image parasite quantification) LoD device have demonstrated its potential as a diagnostic tool, especially for such low-intensity infections. Nevertheless, the device's efficiency has been limited by significant egg loss during sample preparation, low capture efficiency of eggs within the Field of View (FOV), and the presence of larger fecal debris that obstructs effective egg trapping and imaging. In this study, we conducted a set of laboratory experiments using model polystyrene particles and purified STH eggs to improve the sample preparation protocol. These experiments include the entire SIMPAQ procedure starting from sample preparation, infusing it into the LoD device, centrifugation, delivering the (model) eggs to the FOV, capturing an image, and analyzing it. We analyzed egg losses at each step of the procedure following the "standard" protocol, then elaborated and tested alternative, more efficient procedures. The resulting modified protocol significantly minimized particle and egg loss and reduced the amount of debris in the disk, thus enabling effective egg capture and clear images in the FOV, increasing the reliability of the diagnostic results.
土源性蠕虫对全球健康构成重大挑战，在热带和亚热带地区尤为如此。当前的诊断标准是对粪便涂片进行显微镜检查，但该方法在检测低强度感染方面缺乏敏感性。诸如盘式实验室（LoD）技术等创新解决方案正在兴起，在检测低强度感染方面显示出前景。使用我们的SIMPAQ（单图像寄生虫定量）LoD设备进行的现场测试证明了其作为诊断工具的潜力，特别是对于此类低强度感染。然而，该设备的效率受到样本制备过程中大量虫卵损失、视野（FOV）内虫卵捕获效率低以及存在较大粪便残渣阻碍有效虫卵捕获和成像的限制。在本研究中，我们使用聚苯乙烯模型颗粒和纯化的土源性蠕虫虫卵进行了一系列实验室实验，以改进样本制备方案。这些实验包括从样本制备开始的整个SIMPAQ程序，将其注入LoD设备、离心、将（模型）虫卵输送到FOV、捕获图像并进行分析。我们按照“标准”方案分析了该程序每个步骤中的虫卵损失，然后制定并测试了更高效的替代程序。由此产生的改进方案显著减少了颗粒和虫卵损失，并减少了盘中的残渣量，从而能够在FOV中有效捕获虫卵并获得清晰图像，提高了诊断结果的可靠性。
