Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy.
Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
Infect Dis Poverty. 2021 May 25;10(1):76. doi: 10.1186/s40249-021-00858-9.
Implementation of control programmes for Strongyloides stercoralis infection is among the targets of the World Health Organization Roadmap to 2030. Aim of this work was to evaluate the possible impact in terms of economic resources and health status of two different strategies of preventive chemotherapy (PC) compared to the current situation (strategy A, no PC): administration of ivermectin to school-age children (SAC) and adults (strategy B) versus ivermectin to SAC only (strategy C).
The study was conducted at the IRCCS Sacro Cuore Don Calabria hospital, Negrar di Valpolicella, Verona, Italy, at the University of Florence, Italy, and at the WHO, Geneva, Switzerland, from May 2020 to April 2021. Data for the model were extracted from literature. A mathematical model was developed in Microsoft Excel to assess the impact of strategies B and C in a standard population of 1 million subjects living in a strongyloidiasis endemic area. In a case base scenario, 15% prevalence of strongyloidiasis was considered; the 3 strategies were then evaluated at different thresholds of prevalence, ranging from 5 to 20%. The results were reported as number of infected subjects, deaths, costs, and Incremental-Effectiveness Ratio (ICER). A 1-year and a 10-year horizons were considered.
In the case base scenario, cases of infections would reduce dramatically in the first year of implementation of PC with both strategy B and C: from 172 500 cases to 77 040 following strategy B and 146 700 following strategy C. The additional cost per recovered person was United States Dollar (USD) 2.83 and USD 1.13 in strategy B and C, respectively, compared to no treatment in the first year. For both strategies, there was a downtrend in costs per recovered person with increasing prevalence. The number of adverted deaths was larger for strategy B than C, but cost to advert one death was lower for strategy C than B.
This analysis permits to estimate the impact of two PC strategies for the control of strongyloidiasis in terms of costs and adverted infections/deaths. This could represent a basis on which each endemic country can evaluate which strategy can be implemented, based on available funds and national health priorities.
实施旋毛虫病控制规划是世界卫生组织 2030 年路线图的目标之一。本研究旨在评估与现行方案（方案 A，无预防性化疗）相比，两种不同预防性化疗（PC）策略（方案 B，对学龄儿童和成人使用伊维菌素；方案 C，仅对学龄儿童使用伊维菌素）在经济资源和健康状况方面可能产生的影响。
该研究于 2020 年 5 月至 2021 年 4 月在意大利维罗纳的萨科库罗塞多卡尔布利亚 IRCCS 医院、意大利佛罗伦萨大学和世界卫生组织日内瓦办事处进行。模型数据取自文献。采用 Microsoft Excel 建立数学模型，评估策略 B 和 C 在居住在旋毛虫病流行地区的 100 万标准人群中的影响。在病例基础情景中，考虑到旋毛虫病的患病率为 15%；然后，在不同的患病率阈值（5%至 20%）下，对这 3 种策略进行了评估。结果以受感染者、死亡人数、成本和增量效益比（ICER）的数量表示。考虑了 1 年和 10 年的时间范围。
在病例基础情景中，在实施 PC 的第一年，策略 B 和 C 均能显著减少感染病例：从 172500 例降至 146700 例。与不治疗相比，实施策略 B 和 C 时，第 1 年每个康复者的额外成本分别为 2.83 美元和 1.13 美元。对于这两种策略，随着患病率的增加，每个康复者的成本呈下降趋势。策略 B 导致的避免死亡人数多于策略 C，但策略 C 避免每例死亡的成本低于策略 B。
本分析可根据成本和感染/死亡人数的减少来评估两种旋毛虫病 PC 策略的控制效果。这可以作为每个流行国家根据可用资金和国家卫生重点评估可以实施哪种策略的基础。
