London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK.
Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
Parasit Vectors. 2024 Aug 21;17(1):355. doi: 10.1186/s13071-024-06422-2.
This paper documents changes in the prevalence and intensity of soil-transmitted helminth (STH) infections in the Geshiyaro project in the Wolaita zone of Southern Ethiopia.
The Geshiyaro project comprises three intervention arms. Arm 1 is subdivided into the Arm 1 pilot (one district) and Arm 1 (four other districts), both receiving integrated community-wide mass drug administration MDA (cMDA) with intensive water, sanitation, and hygiene (WaSH) interventions. Arm 2 involves 18 districts with cMDA interventions plus the existing government-led One WaSH program, while Arm 3 serves as a control with school-based MDA (sMDA) interventions plus the existing government-led One WaSH program in three districts. The study is designed as a cohort investigation over time, with the establishment of longitudinal sentinel sites where infection levels are assessed annually. A total of 45 longitudinal parasitological surveillance sentinel sites are being used across all three intervention arms to monitor STH prevalence and intensity of infection. From each of the 45 sentinel sites, 150 individuals were randomly selected, stratified by age and gender. The t-test and analysis of variance (ANOVA) were employed to compare infection prevalence and intensity across the three study arms over time.
The prevalence of STH decreased significantly from 34.5% (30.6%, 38.5%) in 2019 to 10.6% (8.3%, 13.4%) in 2022/2023 (df = 1, P < 0.0001) in the Arm 1 pilot, from 27.4% (25.2%, 29.7%) in 2020 to 5.5% (4.4%, 6.7%) in 2023 (df = 1, P < 0.0001) in Arm 1, from 23% (21.3%, 24.8%) in 2020 to 4.5% (3.7%, 5.3%) in 2023 (df = 1, P < 0.001) in Arm 2, and from 49.6% (47.4%, 51.7%) in 2021 to 26.1% in 2023 (df = 1, P < 0.0001) in Arm 3. The relative reduction in the prevalence of any STH was the highest in the arms employing cMDA, namely Arm 2, with a decrease of 82.5% (79.3%, 84.2%), followed by Arm 1 with a reduction of 80.1% (75.3%, 84.6%), and then the Arm 1 pilot with a decrease of 69.4% (60.1%. 76.6%). Arm 3 employing sMDA had the lowest decrease, with a reduction of 46.9% (43.6%, 51%). The mean intensity of infection (based on Kato-Katz egg count measures) for Ascaris lumbricoides species, which was the dominant STH species present in the study area, decreased significantly in Arms 1 and 2, but only slightly in Arm 3. The prevalence of hookworm and Trichuris trichiura infections were found to be very low in all arms but also decreased significantly.
The reduction in the prevalence and intensity of STH in Arms 1 and 2 revealed steady progress towards transmission interruption based on cMDA intervention, but additional efforts with MDA coverage and WaSH interventions are needed to achieve a prevalence threshold < 2% based on the quantitative polymerase chain reaction (qPCR) diagnostic method.
本文记录了埃塞俄比亚南部沃莱塔地区 Geshiyaro 项目中土壤传播性蠕虫（STH）感染的流行率和强度变化。
Geshiyaro 项目包括三个干预组。第 1 组分为第 1 组试点（一个区）和第 1 组（其他四个区），均接受综合社区范围的大规模药物驱虫（MDA），并辅以密集的水、环境卫生和个人卫生（WaSH）干预。第 2 组包括 18 个接受 MDA 干预的区，外加现有的政府主导的 One WaSH 项目，第 3 组为对照，采用基于学校的 MDA（sMDA）干预，外加现有的政府主导的 One WaSH 项目在三个区。该研究设计为随时间进行的队列研究，建立了纵向哨点，每年评估感染水平。在所有三个干预组中，共有 45 个纵向寄生虫学监测哨点用于监测 STH 的流行率和感染强度。从每个哨点随机抽取 150 人，按年龄和性别分层。采用 t 检验和方差分析（ANOVA）比较三个研究组随时间的感染流行率和强度。
在 Arm 1 试点中，从 2019 年的 34.5%（30.6%，38.5%）显著下降到 2022/2023 年的 10.6%（8.3%，13.4%）（df=1，P<0.0001）；在 Arm 1 中，从 2020 年的 27.4%（25.2%，29.7%）显著下降到 2023 年的 5.5%（4.4%，6.7%）（df=1，P<0.0001）；在 Arm 2 中，从 2020 年的 23%（21.3%，24.8%）显著下降到 2023 年的 4.5%（3.7%，5.3%）（df=1，P<0.001）；在 Arm 3 中，从 2021 年的 49.6%（47.4%，51.7%）显著下降到 2023 年的 26.1%（df=1，P<0.0001）。采用 cMDA 的干预措施的 arms 中，任何 STH 流行率的相对降低幅度最高，即 Arm 2，降低了 82.5%（79.3%，84.2%），其次是 Arm 1，降低了 80.1%（75.3%，84.6%），然后是 Arm 1 试点，降低了 69.4%（60.1%，76.6%）。采用 sMDA 的 Arm 3 降低幅度最低，为 46.9%（43.6%，51%）。基于加藤-Katz 卵计数测量的 Ascaris lumbricoides 物种感染的平均强度（主要的 STH 物种）在 Arms 1 和 2 中显著降低，但在 Arm 3 中仅略有降低。在所有 arms 中，钩虫和 Trichuris trichiura 感染的流行率均发现非常低，但也显著降低。
在 Arms 1 和 2 中 STH 的流行率和强度的降低表明，基于 MDA 干预的传播中断取得了稳步进展，但需要进一步加强 MDA 覆盖范围和 WaSH 干预，以达到基于定量聚合酶链反应（qPCR）诊断方法的流行率阈值<2%。
