Faculté des Sciences de la Santé, Université de Lomé, Boulevard Eyadema, 01BP 1515, Lomé, Togo.
Ministère de la Santé et de l'Hygiène Publique Togo, Angle Avenue Sarakawa et Avenue du 24 Janvier, 01BP 336, Lomé, Togo.
Parasit Vectors. 2021 Jan 6;14(1):23. doi: 10.1186/s13071-020-04535-y.
The World Health Organization has targeted lymphatic filariasis (LF) for elimination as a public health problem and recommends, among other measures, post-elimination surveillance of LF. The identification of sensitive and specific surveillance tools is therefore a research priority. The Wuchereria bancrofti-specific antigen Wb123-based enzyme-linked immunosorbent assay (Wb123 ELISA) detects antibodies to the recombinant Wb123 antigen of W. bancrofti and may be useful as a surveillance tool for LF. Six years after stopping mass drug administration to eliminate LF and recording successful results on two post-treatment transmission assessment surveys, a study was conducted in Togo aimed at helping to identify the role of the Wb123 ELISA in post-validation surveillance of LF.
This was a cross-sectional study in eight previously LF-endemic districts and one non-endemic district in Togo. In each sub-district of these nine districts, two schools were selected and 15 children aged 6 to 9 years old at each school provided finger-stick blood for testing for antibodies to Wb123 using the Filaria Detect™ IgG4 ELISA kit® (InBios, International, Inc., Seattle, WA, USA).
A total of 2654 children aged 6 to 9 years old were tested in 134 schools in the nine districts. Overall, 4.7% (126/2654) children tested positive for antibodies to the Wb123 antigen of W. bancrofti. The prevalence of Wb123 antibodies varied across the eight previously endemic LF districts, from 1.56 to 6.62%. The highest prevalence, 6.99%, was found in the non-endemic district, but this was not significantly different from the average of all the LF districts (4.49%, P = 0.062).
The Wb123 ELISA was positive in 4.7% of Togolese school-age children who were almost certainly unexposed to LF. This apparent lack of specificity in the Togo context makes it difficult to establish a seroprevalence threshold that could serve to signal LF resurgence in the country, precluding the use of this test for post-validation surveillance in Togo. There remains a need to develop a useful and reliable test for post-elimination surveillance for LF in humans.
世界卫生组织已将淋巴丝虫病（LF）定为消除公共卫生问题的目标，并建议采取包括消除后监测在内的多项措施。因此，确定敏感和特异的监测工具是一个研究重点。基于班氏丝虫特异性抗原 Wb123 的酶联免疫吸附试验（Wb123 ELISA）检测针对班氏丝虫 Wb123 重组抗原的抗体，可能作为 LF 监测工具有用。在停止大规模药物治疗以消除 LF 并在两次治疗后传播评估调查中取得成功结果六年后，在多哥进行了一项研究，旨在帮助确定 Wb123 ELISA 在 LF 验证后监测中的作用。
这是在多哥的 8 个以前流行 LF 的区和 1 个非流行区进行的横断面研究。在这 9 个区的每个分区中，选择了 2 所学校，每所学校的 15 名 6 至 9 岁的儿童提供指血，使用 Filaria Detect™ IgG4 ELISA 试剂盒®（InBios，International，Inc.，西雅图，WA，USA）检测针对 Wb123 的抗体。
在 9 个区的 134 所学校中，共检测了 2654 名 6 至 9 岁的儿童。总体而言，有 4.7%（126/2654）的儿童对 W. bancrofti 的 Wb123 抗原抗体检测呈阳性。Wb123 抗体的流行率在以前流行 LF 的 8 个区之间有所不同，范围为 1.56%至 6.62%。非流行区的流行率最高，为 6.99%，但与所有 LF 区的平均值（4.49%）相比，差异无统计学意义（P=0.062）。
在几乎肯定未接触过 LF 的多哥学龄儿童中，有 4.7%的儿童对 Wb123 ELISA 呈阳性。在多哥背景下，这种明显缺乏特异性使得难以确定可用于提示该国 LF 复发的血清流行率阈值，从而排除了在该国使用该检测方法进行验证后监测的可能性。仍然需要开发一种用于人类消除后 LF 监测的有用且可靠的检测方法。
