Entomology data from Lymphatic filariases and soil-transmitted helminthiases in Sri Lanka: the challenge of eliminating residual pockets of transmission

Sri Lanka has successfully met the challenge of controlling both lymphatic filariasis (LF) and soil-transmitted helminthiases (STH) as public health problems. The primary public health strategy for combatting both conditions has been preventive chemotherapy. The national programme for the elimination of LF implemented five annual rounds of mass chemotherapy in the endemic districts from 2002 to 2006 using a combination of diethylcarbamazine and albendazole. The overall microfilaria rate declined from 0.21% in 2001 before the mass chemotherapy, to 0.06% in 2016, at declaration of elimination of LF as a public health problem by the World Health Organization. Currently Sri Lanka is in the phase of post-validation surveillance. Achieving control of STH has been more difficult. Mass deworming programmes have been implemented for nearly a century, and national-level surveys reported prevalence rates declining from 6.9% in 2003 to 1% in 2017. However, neither of these infections has been completely eliminated. A situation analysis indicates continued transmission of both among high-risk communities. This paper explores the reasons for persistence of transmission of both LF and STH in residual pockets and the measures that are required to achieve long-term control, or perhaps even interrupt transmission in Sri Lanka.This article is part of the theme issue ‘Challenges in the Fight Against Neglected Tropical Diseases’.

斯里兰卡已成功应对将淋巴丝虫病（lymphatic filariasis, LF）与土源性蠕虫病（soil-transmitted helminthiases, STH）作为公共卫生问题进行防控的挑战。针对这两类疾病的核心公共卫生防控策略为预防性化疗。2002年至2006年间，该国针对淋巴丝虫病消除的国家计划在流行区开展了5轮年度集体化疗，联合使用乙胺嗪与阿苯达唑。在世界卫生组织（World Health Organization）宣布将淋巴丝虫病作为公共卫生问题消除的2016年，总体微丝蚴率已从集体化疗前2001年的0.21%降至0.06%。目前，斯里兰卡已进入验证后监测阶段。土源性蠕虫病的防控则更为棘手。尽管集体驱虫计划已推行近百年，全国性调查显示其患病率已从2003年的6.9%降至2017年的1%，但这两类感染均未被完全消除。态势分析显示，两类疾病在高风险社区仍存在持续传播。本文探讨了斯里兰卡淋巴丝虫病与土源性蠕虫病在残留疫点持续传播的原因，以及实现长期防控、甚至阻断传播所需采取的措施。本文属于"抗击被忽视热带病面临的挑战"专题栏目文章。