Feasibility of utilizing the SD BIOLINE Onchocerciasis IgG4 rapid test in onchocerciasis surveillance in Senegal

As effective onchocerciasis control efforts in Africa transition to elimination efforts, different diagnostic tools are required to support country programs. Senegal, with its long standing, successful control program, is transitioning to using the SD BIOLINE Onchocerciasis IgG4 (Ov16) rapid test over traditional skin snip microscopy. The aim of this study is to demonstrate the feasibility of integrating the Ov16 rapid test into onchocerciasis surveillance activities in Senegal, based on the following attributes of acceptability, usability, and cost. A cross-sectional study was conducted in 13 villages in southeastern Senegal in May 2016. Individuals 5 years and older were invited to participate in a demographic questionnaire, an Ov16 rapid test, a skin snip biopsy, and an acceptability interview. Rapid test technicians were interviewed and a costing analysis was conducted. Of 1,173 participants, 1,169 (99.7%) agreed to the rapid test while 383 (32.7%) agreed to skin snip microscopy. The sero-positivity rate of the rapid test among those tested was 2.6% with zero positives 10 years and younger. None of the 383 skin snips were positive for Ov microfilaria. Community members appreciated that the rapid test was performed quickly, was not painful, and provided reliable results. The total costs for this surveillance activity was $22,272.83, with a cost per test conducted at $3.14 for rapid test, $7.58 for skin snip microscopy, and $13.43 for shared costs. If no participants had refused skin snip microscopy, the total cost per method with shared costs would have been around $16 per person tested. In this area with low onchocerciasis sero-positivity, there was high acceptability and perceived value of the rapid test by community members and technicians. This study provides evidence of the feasibility of implementing the Ov16 rapid test in Senegal and may be informative to other country programs transitioning to Ov16 serologic tools.随着非洲盘尾丝虫病（onchocerciasis）防控工作向消除阶段转型，各国疾病控制项目亟需适配的新型诊断工具以支撑工作开展。塞内加尔凭借长期开展且成效显著的盘尾丝虫病防控项目，正逐步用SD BIOLINE盘尾丝虫病IgG4（Ov16）快速检测试剂替代传统的皮肤剪样镜检（skin snip microscopy）。 本研究旨在结合可接受性、实用性与成本三大评价维度，验证将Ov16快速检测试剂整合入塞内加尔盘尾丝虫病监测工作的可行性。 2016年5月，研究团队在塞内加尔东南部的13个村庄开展了一项横断面研究（cross-sectional study）。研究招募5岁及以上居民参与，内容包括填写人口统计学问卷、接受Ov16快速检测、皮肤活检取样以及可接受性访谈；同时对快速检测操作人员进行访谈，并开展成本分析。 本次研究共纳入1173名参与者，其中1169人（99.7%）同意接受快速检测，仅383人（32.7%）同意接受皮肤剪样镜检。受检人群中，快速检测的血清阳性率（sero-positivity rate）为2.6%，10岁及以下人群未检出阳性结果；383份皮肤剪样样本均未检出盘尾丝虫微丝蚴（microfilaria）。 社区居民反馈，快速检测操作便捷、无痛苦且结果可靠，认可度较高。本次监测活动的总成本为22272.83美元，其中单次快速检测成本为3.14美元，单次皮肤剪样镜检成本为7.58美元，共享成本为13.43美元。若所有参与者均同意接受皮肤剪样镜检，分摊共享成本后，每人次检测的总成本约为16美元。 在该盘尾丝虫病血清阳性率较低的地区，社区居民与检测操作人员均对快速检测表现出较高的接受度与价值认同感。本研究证实了在塞内加尔推广Ov16快速检测试剂的可行性，可为其他计划转向使用Ov16血清学检测工具的国家疾病控制项目提供参考依据。