Rahman Mohammad A, Yahathugoda Thishan C, Tojo Bumpei, Premaratne Prasad, Nagaoka Fumiaki, Takagi Hidekazu, Kannathasan Selvam, Murugananthan Arumugam, Weerasooriya Mirani V, Itoh Makoto
Filariasis Research Training and Service Unit (FRTSU), Department of Parasitology, Faculty of Medicine, University of Ruhuna, Sri Lanka.
Laboratory of Molecular Immunology, The University of Tokyo, Japan.
Parasitol Int. 2019 Feb;68(1):73-78. doi: 10.1016/j.parint.2018.10.003. Epub 2018 Oct 9.
Lymphatic filariasis (LF) has been declared eliminated in Sri Lanka in September 2016. To maintain elimination status, a surveillance system to detect hidden endemic foci or LF resurgence is of highest priority. In this paper, we have reported an investigation of LF transmission in Trincomalee district where a surveillance program was not carried out due to 30 years of civil unrest. Proposed surveillance system included, measurement of anti-filarial IgG4 in urine of schoolchildren in areas where LF transmission could exist and assessment of circulating filarial antigen (CFA) and microfilaria (mf) in all urine antibody positive schoolchildren, their family members and 10-15 neighbours of each urine antibody positive household. Spatial distribution of the anti-filarial antibody titers in urine in a high antibody suspected area was analyzed using GPS logger data. Among 2301 school children from 11 schools studied, 41 (1.8%) urine antibody positives were found. The antibody positive rates of the schools ranged between 0 and 4.0%. Nine of the 630 (1.4%) examined became positive for CFA but were negative for mf. Although there were no mf positives, positive CFA and antibody results indicated the existence of Wuchereria bancrofti in Trincomalee. Highest antibody titres in an area correlated with the prevalences of urine antibodies and CFA. Spatial analysis showed LF transmission foci. Therefore, a combination of the non-invasive methods, urine ELISA and GPS mapping, will be a new effective surveillance system to identify hidden LF transmission foci.
2016年9月，斯里兰卡宣布已消除淋巴丝虫病（LF）。为维持消除状态，检测隐藏的流行病灶或LF卷土重来的监测系统至关重要。在本文中，我们报告了对亭可马里区LF传播情况的调查，该地区因30年的内乱未开展监测项目。提议的监测系统包括，在可能存在LF传播的地区检测学童尿液中的抗丝虫IgG4，并对所有尿液抗体呈阳性的学童、其家庭成员以及每个尿液抗体呈阳性家庭的10 - 15名邻居进行循环丝虫抗原（CFA）和微丝蚴（mf）评估。利用GPS记录仪数据分析高抗体疑似区域尿液中抗丝虫抗体滴度的空间分布。在研究的11所学校的2301名学童中，发现41名（1.8%）尿液抗体呈阳性。各学校的抗体阳性率在0至4.0%之间。在630名接受检查的人员中，有9名（1.4%）CFA呈阳性但mf呈阴性。尽管没有mf呈阳性的情况，但CFA和抗体阳性结果表明亭可马里存在班氏吴策线虫。一个地区的最高抗体滴度与尿液抗体和CFA的流行率相关。空间分析显示了LF传播病灶。因此，尿液ELISA和GPS绘图等非侵入性方法相结合，将成为识别隐藏的LF传播病灶的新型有效监测系统。
