A mathematical model for the control of swimmer's itch
A mathematical model for the control of swimmer's itch
复制标题
控制游泳者瘙痒的数学模型
DOI：
10.1111/nrm.12275
复制
发表时间：
2020
影响因子：
1.6
通讯作者：
Sandland, G. J.
中科院分区：
文献类型：
--
作者：
Peirce, J. P.;Pellett, J. J.;Sandland, G. J.
游泳者瘙痒症是一种由扁形虫寄生虫引起的新兴疾病，扁形虫寄生虫通常将水鸟作为最终宿主。当寄生虫幼虫穿透人体皮肤时，它们会引发局部炎症，导致强烈的瘙痒。由于全球游泳者瘙痒症的发生率明显增加及其对娱乐活动和相关收入的后续影响，最近对这一问题的关注日益增加。过去的研究已经确定普通秋沙鸭是美国这些蠕虫的关键最终宿主;一些蜗牛物种作为中间宿主。尽管之前控制游泳者瘙痒的尝试是针对蜗牛的，但一些努力集中在用驱虫药吡喹酮治疗水鸟上。我们构建了一个数学模型的游泳者的痒和治疗感染秋沙鸭种群。我们的目标是确定秋沙鸭治疗方案，最大限度地减少感染蜗牛的数量，从而降低人类感染的风险。鸟类宿主的最优控制是解析定义的，我们包括假设不同的资源分配策略的数值模拟。这项研究的结果可能有助于确定降低秋沙鸭感染率的治疗方案，并最终减少整个中西部淡水系统中游泳者瘙痒的发生。吡喹酮治疗频率应增加秋沙鸭抵达湖上的持续治疗分配大量资源用于治疗秋沙鸭，预计受感染的鸟类会急剧下降，然后在驻留期的剩余时间内保持接近于零。这种方法减少了秋沙鸭的寄生虫感染，并在娱乐活动高峰期将蜗牛感染保持在理想范围内。因此，游泳者瘙痒的人类病例预计将很低，甚至不存在。此外，我们的治疗寿命计算表明，随后的吡喹酮剂量将不需要数年。在更有限的资源下，每天治疗的鸟类数量在整个驻留期间要少得多;然而，即使在这种情况下，（相当于大约每5天治疗一只鸡），模拟的感染秋沙鸭密度被降低到直到休闲期结束蜗牛感染仍低于流行水平的程度。与高资源选项相比，治疗寿命较短，但仍然延长了122天，进入第2季（治疗后）。我们还使用我们的模型来调查湖泊管理者和/或联邦机构可能会在给定湖泊上持续治疗秋沙鸭的时间方面被征税的情况。一个科学家可能只有一天（或两天）的时间给鸟类服用吡喹酮，而不是在鸟类居住期间连续服用吡喹酮。如果在一天内可以治疗到达的鸟类总数的77%，我们建议在秋沙鸭数量达到可以成功治疗的最大数量时使用吡喹酮。此外，模型模拟表明，如果管理人员能够治疗大量鸟类，他们应该等到迁徙期结束。
Swimmer's itch is an emerging disease caused by flatworm parasites that often use water birds as definitive hosts. When parasite larvae penetrate human skin they initiate localized inflammation that leads to intense itching. Concerns about this issue have been growing recently due to an apparent increase in the global occurrence of swimmer's itch and its subsequent impacts on recreational activities and associated revenues. Past study has identified the common merganser as a key definitive host for these worms in the United States; a number of snail species serve as intermediate hosts. Although previous attempts at controlling swimmer's itch have targeted snails, a handful of efforts have concentrated on treating water birds with the anthelmintic drug, praziquantel. We construct a mathematical model of swimmer's itch and its treatment within the infected merganser population. Our goal is to identify merganser treatment regimes that minimize the number of infected snails thereby reducing the risk of human infections. Optimal control of bird hosts is defined analytically and we include numerical simulations assuming different resource‐allocation strategies. Results from the study may help identify treatment protocols that lower merganser infection rates and ultimately reduce the occurrence of swimmer's itch in freshwater systems throughout the Midwest.Recommendations for Resource ManagersRegardless of the time and monetary resources available, praziquantel treatment frequency should increase as mergansers arrive on the lake with continued treatments (albeit at reduced levels) until the end of the residency period.Allocating plenty of resources towards the treatment of mergansers predicted a sharp drop in infected birds, which then remained close to zero throughout the remainder of the residency period. This approach reduced schistosome infection in mergansers and kept snail infections within the idealized range during times of peak recreational activity. Consequently, human cases of swimmer's itch would be expected to be low to nonexistent. Furthermore, our treatment‐longevity computation suggested that subsequent praziquantel dosing would not be required for a number of years.Under more limited resources, the number of birds treated per day was much smaller throughout the residency period; however, even under these circumstances (which equated to treating approximately one bird every 5 days), simulated infected merganser densities were reduced to the point where snail infections remained below epidemic levels through to the end of the recreational period. Treatment longevity was shorter compared with the high‐resource option, but still extended 122 days into Season 2 (posttreatment).We also used our model to investigate situations where lake managers and/or federal agencies might be taxed in terms of the time available to continuously treat mergansers on a given lake. An individual scientist may only have a single day (or two) to dose birds, rather than continuously administering praziquantel throughout the birds' residency period. If <77% of the total number of arriving birds can be treated in a single day, we recommend praziquantel administrations when the number of mergansers reaches the maximum that can be successfully treated. In addition, model simulations demonstrate that if managers are able to treat a large number of birds, they should wait until the end of the migration period.
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DOI：
10.1016/j.cam.2016.11.002
发表时间：
2017-07-01
影响因子：
2.4
作者：
Lemos-Paiao, Ana P.;Silva, Cristiana J.;Torres, Delfim F. M.
通讯作者：
Torres, Delfim F. M.
游泳者的瘙痒：欧洲的病因、影响和风险因素。
影响因子：
9.6
作者：
M. Soldánová;C. Selbach;M. Kalbe;A. Kostadinova;B. Sures
通讯作者：
B. Sures
影响因子：
4.8
作者：
DEWITT, RM
通讯作者：
DEWITT, RM
影响因子：
4.2
作者：
Chai JY
通讯作者：
Chai JY
DOI：
10.1139/f70-149
发表时间：
1970-01-01
期刊：
JOURNAL OF THE FISHERIES RESEARCH BOARD OF CANADA
影响因子：
--
作者：
ARTHUR, JW;LEONARD, EN
通讯作者：
LEONARD, EN