Infectious disease can reduce labor productivity and incomes, trapping subpopulations in a vicious cycle of ill health and poverty. Efforts to boost African farmers’ agricultural production through fertilizer use can inadvertently promote the growth of aquatic vegetation that hosts disease vectors. Recent trials established that removing aquatic vegetation habitat for snail intermediate hosts reduces schistosomiasis infection rates in children, while converting the harvested vegetation into compost boosts agricultural productivity and incomes. We develop a bioeconomic model that interacts an analytical microeconomic model of agricultural households’ behavior, health status, and incomes over time with a dynamic model of schistosomiasis disease ecology. We calibrate the model with field data from northern Senegal. We show analytically and via simulation that local conversion of invasive aquatic vegetation to compost changes the feedback among interlinked disease, aquatic, and agricultural systems, reducing schistosomiasis infection and increasing incomes relative to the current status quo, in which villagers rarely remove aquatic vegetation. Aquatic vegetation removal disrupts the poverty-disease trap by reducing habitat for snails that vector the infectious helminth and by promoting the production of compost that returns to agricultural soils nutrients that currently leach into surface water from on-farm fertilizer applications. The result is healthier people, more productive labor, cleaner water, more productive agriculture, and higher incomes. Our model illustrates how this ecological intervention changes the feedback between the human and natural systems, potentially freeing rural households from poverty-disease traps.

中文翻译：

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模拟水生植被移除如何以及为何可以使农村家庭摆脱贫困疾病陷阱


传染病会降低劳动生产率和收入，使亚群陷入健康不佳和贫困的恶性循环中。通过化肥使用来促进非洲农民的农业生产的努力可能会无意中促进承载疾病媒介的水生植被的生长。最近的试验确定，移除蜗牛中间宿主的水生植被栖息地可降低儿童血吸虫病感染率，同时将收获的植被转化为堆肥可以提高农业生产力和收入。我们开发了一个生物经济模型，该模型将农业家庭行为、健康状况和收入随时间变化的分析微观经济模型与血吸虫病疾病生态学的动态模型进行交互。我们使用来自塞内加尔北部的现场数据校准模型。我们通过分析和模拟表明，入侵水生植被在当地转化为堆肥改变了相互关联的疾病、水生和农业系统之间的反馈，减少了血吸虫病感染并增加了相对于当前现状的收入，在目前现状中，村民很少移除水生植被。水生植被清除减少了传播传染性蠕虫的蜗牛的栖息地，并促进了堆肥的产生，这些堆肥将目前从农场施肥中渗入地表水的养分返回到农业土壤中，从而打破了贫困-疾病陷阱。其结果是更健康的人们、更高效的劳动力、更清洁的水、更高效的农业和更高的收入。我们的模型说明了这种生态干预如何改变人类和自然系统之间的反馈，从而有可能使农村家庭摆脱贫困疾病陷阱。