埃塞俄比亚二十年的土壤传播的蠕虫和斑点体感染控制

土壤传播的蠕虫和血吸虫病是最普遍的被忽视的热带疾病。仅在埃塞俄比亚,他们分别感染了约3600万和500万个人。埃塞俄比亚设定了雄心勃勃的消除目标。一项新的系统审查分析了过去20年来国家取得的进展。

这篇博客文章是系列的一部分,其中包含在lcntdrCollection: Advances in scientific research for NTD control,,,,伦敦被忽视的热带疾病研究中心(lcntdr)。请继续关注Twitter上的更新@bugbittentweetsand@NTDResearch。您可以在系列中找到其他帖子here


土壤传播的蠕虫和血吸虫病

土壤传播的蠕虫(STH)and血吸虫病(SCH)是全球最广泛的被忽视的热带疾病(NTD),估计有15亿和2.4亿个人在全球范围内被感染。在埃塞俄比亚,目前有3600万和500万人感染了STH和SCH。STH集体指的是round虫(ascaris lumbricoides;al),鞭子(Trichuris Trichiura;TT), hookworm (Necator Americanus,,,,Ancylostoma duodeNaleandAncylostoma ceylanicum;HW)和Thusworm(强叶蛋白酶刺;SS). The血吸虫流血引起泌尿生殖器(血吸虫血吸虫病;SH) or intestinal (血吸虫mansoni;SM)SCH。通常,STH和SCH卵在感染个体的粪便中排出,并污染了土壤和水源。因此,它们的存在被认为是卫生和卫生不良的代理标记。

埃塞俄比亚设定了雄心勃勃的国家目标,即在2020年之前将STH和SCH作为公共卫生问题取消,并在2025年破坏其传播。最近的评论presented epidemiological data on STH and SCH prevalence, stratified by region, species, age and diagnostics.

埃塞俄比亚土壤传播的蠕虫和血吸虫病流行数字。按年龄组按年龄组,埃塞俄比亚的STH和SCH患病率,流行病的数量(地区)以及根据2017年发布的数据需要治疗的人们。来自Maddren,Phillips,Ower等。(2021)。

Bringing down the worms: STH & SCH trends in different regions of Ethiopia

The systematic review of published studies between 2000-2020 identified 267 datasets suitable for data extraction. All nine Ethiopian regions reported STH and SCH prevalence, the majority of which were reported in Amhara (38%). Interestingly, sample population focus has shifted over time, moving from community-wide perspectives, to school-aged children (SAC) and pre-SAC.

A total of 402,189 stool samples extracted from the 267 datasets informed the resultant parasite prevalence and intensity measures used for the analysis. Parasite prevalence decreased over time for most species, as shown in the following graph.

STH和SCH的患病率在1994年至2019年之间。阿斯卡里斯·隆布里塞德(Al; a),trichuris trichiura(tt; b),钩虫(hw; c),strongyloide stercoralis(ss; d),曼森(Scistosoma Mansoni(SMSM; sm;e), and Schistosoma haematobium (SH; f) infections between 1994 and 2019. Pearson’s correlation coefficient (r; top right corner of each plot with associated p-value) was used to measure the linear correlation between parasite prevalence and study date. Study populations, differentiating between pre-school-aged children (pre-SAC), SAC and community-wide study populations, are indicated by different colours, whilst point size indicates study population size (see legend) (g). The trend line was not weighted by sample size. Note the SS graph y-axis range is from 0 to 70, and differs from that of the other plots.

The most statistically significant decrease was demonstrated by TT (34–2%), whilst a significant reduction was also seen in SM (45–14%), AL (34–11%) and SH (35–6%).

下图显示了随时间分层的流行率,突出了区域成功和需要进一步关注的区域成功。在Amhara中看到了最大的寄生虫减少,TT,SM和AL分别减少了99%,83%和80%,而SNNPR则HW,TT,SM和AL减少了98%,94%,86%,86%,86%,86%,86%和80%。仅在HW的Tigray中才有显着的患病率增加。

a–e Regional prevalence change in Amhara (yellow), Oromia (red), Southern Nations, Nationalities and Peoples’ Region (SNNPR; turquoise) and Tigray (grey). Prevalence change of AL (a), TT (b), HW (c), SS (d) and SM (e) infections between 1994 and 2019, stratified by region for Amhara (n = 102), Oromia (n = 67), SNNPR (n = 59) and Tigray (n = 21). Pearson’s correlation coefficient (top right corner of each plot with associated p-value) was used to measure the linear correlation over time between parasite prevalence and study date.

降低蠕虫:埃塞俄比亚不同年龄段的STH&SCH趋势。

最值得注意的是,历史SAC-focused大规模药物administration (MDA) is reflected in the age-prevalence distribution of parasite burden. AL and TT showed the most pronounced deviation from the typical distribution of infection, as higher parasite burdens were seen in adults compared to pre-SAC, SAC and adolescents. HW showed higher than expected infection levels in SAC, yet remained typically high in adults. This chiefly demonstrates the interaction of natural age-prevalence distributions on MDA efficacy. AL and TT are normally found in higher burdens in pre-SAC and SAC age groups, which decreases in adulthood. Therefore, SAC-focused MDA has successfully reduced the SAC parasite burden whilst simultaneously creating an infection reservoir in adults.

降低蠕虫:诊断需要进步以消除

患病率的总体下降证明了埃塞俄比亚公共卫生研究所为消除STH和SCH所做的激烈努力。但是,随着寄生虫患病率降低,所采用的诊断和流行病学测量的敏感性将需要增加,以便准确地报告国家进展。由于流行率与平均感染强度之间的非线性关系,因此,在高强度下,患病率在较高的强度下会忽略不计,因此应重新检查患病率作为主要的流行病学参数。尽管如此,在整个综述的文献中,在20-35%的研究中报告了强度以及患病率。为了改善埃塞俄比亚的控制计划监控,埃塞俄比亚公共卫生研究所可以考虑更新其关键统计定义,以包括WHO建议的强度措施,并培养一个与患病率一起定期测量强度的环境。

总体而言,整个评论中都注意到了19种不同的诊断方法。卡托–卡茨(35%)和正式的以太浓度技术(fect)(5%)主要使用独立或组合使用(6%)。卡托–卡茨灵敏度取决于STH强度。在高强度和低强度设置之间,单幻灯片精度从74–95%降至53-80%。这种敏感性可以通过加倍每个样品读取的幻灯片,低强度设置中的50-80%。A third of reviewed studies used single Kato–Katz slides, demonstrating the need to update Ethiopia’s diagnostic protocol to accurately report the low prevalence desired for elimination.

下一步击落蠕虫的步骤是什么?

本综述提供的流行病学数据表明,当前基于SAC的治疗和控制策略应扩展到社区范围的间隔。为此,将针对成年种群的感染储层,以减少经过治疗的囊的重新感染。这还将使主要以成人为中心的HW感染能够反映AL和TT的患病率降低。随着STH和SCH患病率的降低,当前的监测将受益于强度测量值,并提高诊断敏感性,以准确捕获埃塞俄比亚控制工作的成功。通过年龄和性别对此进行进一步分层,对于评估社区内感染的口袋,至关重要。这将逐渐生成针对年龄/性别群体的针对性指南,以通过寄生虫控制,清洗行为改变活动和有针对性的通信材料来减少与传染材料的相互作用。实施这些变化有可能在不久的将来帮助埃塞俄比亚实现其消除目标。


此博客文章中的研究发表在lcntdrCollection: Advances in scientific research for NTD control,,,,伦敦被忽视的热带疾病研究中心(lcntdr)。该系列已经出版寄生虫和向量自2016年以来,并定期发布新文章。该系列的特点是LCNTDR成员机构及其合作者执行的NTD科学研究的最新进展。它的目的是强调LCNTDR为实现联合国可持续发展目标所做的广泛工作,并支持世界卫生组织路线图2021 - 2030年的目标。

LCNTDR于2013年启动,目的是为NTD提供重点的运营和研究支持。LCNTDR,联合计划自然历史博物馆, 这伦敦卫生与热带医学学院, 这皇家兽医学院, 这Partnership for Child Development, 这SCI基金会((formerly known as the Schistosomiasis Control Initiative) and伦敦帝国学院,进行跨学科研究,以建立围绕NTD计划的设计,实施,监视和评估的证据基础。

您可以在该系列中找到其他博客文章here

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