Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany.
BMC Infect Dis. 2020 Sep 29;20(1):718. doi: 10.1186/s12879-020-05445-1.
Schistosoma antigen detection in urine is a valuable diagnostic approach for schistosomiasis control programmes because of the higher sensitivity compared to parasitological methods and preferred sampling of urine over stool. Highly accurate diagnostics are important in low Schistosoma transmission areas. Pregnant women and young children could particularly benefit from antigen testing as praziquantel (PZQ) can be given to only confirmed Schistosoma cases. This prevents the unborn baby from unnecessary exposure to PZQ. We present here the protocol of a diagnostic study that forms part of the freeBILy project. The aim is to evaluate the accuracy of circulating anodic antigen (CAA) detection for diagnosis of Schistosoma haematobium infections in pregnant women and to validate CAA as an endpoint measure for anti-Schistosoma drug efficacy. The study will also investigate Schistosoma infections in infants.
A set of three interlinked prospective, observational studies is conducted in Gabon. The upconverting phosphor lateral flow (UCP-LF) CAA test is the index diagnostic test that will be evaluated. The core trial, sub-study A, comprehensively evaluates the accuracy of the UCP-LF CAA urine test against a set of other Schistosoma diagnostics in a cross-sectional trial design. Women positive for S. haematobium will proceed with sub-study B and will be randomised to receive PZQ treatment immediately or after delivery followed by weekly sample collection. This approach includes comparative monitoring of CAA levels following PZQ intake and will also contribute further data for safety of PZQ administration during pregnancy. Sub-study C is a longitudinal study to determine the incidence of S. haematobium infection as well as the age for first infection in life-time.
The freeBILy trial in Gabon will generate a comprehensive set of data on the accuracy of the UCP-LF CAA test for the detection of S. haematobium infection in pregnant women and newborn babies and for the use of CAA as a marker to determine PZQ efficacy. Furthermore, incidence of Schistosoma infection in infants will be reported. Using the ultrasensitive diagnostics, this information will be highly relevant for Schistosoma prevalence monitoring by national control programs as well as for the development of medicaments and vaccines.
The registration number of this study is NCT03779347 ( clinicaltrials.gov , date of registration: 19 December 2018).
与寄生虫学方法相比，尿中血吸虫抗原检测具有更高的灵敏度，并且更便于采集尿液样本而不是粪便样本，因此它是血吸虫病控制规划中一种有价值的诊断方法。在低血吸虫传播地区，高度准确的诊断非常重要。孕妇和幼儿特别受益于抗原检测，因为只有在确诊的血吸虫病例中才能使用吡喹酮（PZQ）。这可以防止未出生的婴儿不必要地接触 PZQ。我们在此介绍了作为 freeBILy 项目一部分的诊断研究的方案。该研究的目的是评估循环阳极抗原（CAA）检测诊断孕妇感染埃及血吸虫的准确性，并验证 CAA 作为抗血吸虫药物疗效的终点测量指标。该研究还将调查婴儿中的血吸虫感染。
在加蓬进行了一组三项相互关联的前瞻性观察性研究。上转换磷光体侧向流动（UCP-LF）CAA 测试是评估的指标诊断测试。核心试验、子研究 A 全面评估了 UCP-LF CAA 尿液测试对一系列其他血吸虫病诊断方法的准确性，采用横断面试验设计。检测到埃及血吸虫阳性的妇女将继续进行子研究 B，并随机分为立即或分娩后接受 PZQ 治疗，随后每周采集样本。这种方法包括在 PZQ 摄入后监测 CAA 水平的比较，并将为怀孕期间 PZQ 给药的安全性提供进一步的数据。子研究 C 是一项纵向研究，旨在确定埃及血吸虫感染的发生率以及一生中首次感染的年龄。
加蓬的 freeBILy 试验将产生一系列关于 UCP-LF CAA 测试在检测孕妇和新生儿埃及血吸虫感染中的准确性的综合数据，以及 CAA 作为确定 PZQ 疗效的标志物的用途。此外，还将报告婴儿中血吸虫感染的发生率。使用超灵敏诊断方法，这些信息对国家控制规划进行血吸虫病流行监测以及开发药物和疫苗具有重要意义。
本研究的注册号为 NCT03779347（clinicaltrials.gov，注册日期：2018 年 12 月 19 日）。
