STRESS-MALAWI: Strengthening Resilience against Sleeping Sickness in Malawi

马拉维压力：加强马拉维对昏睡病的抵抗力

• 批准号: MR/V011375/1
• 负责人: Christopher Jones
• 金额: $ 109.35万
• 依托单位: Liverpool School of Tropical Medicine
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FV011375%2F1
• 关键词: STRESS; MALAWI; Strengthening; Resilience; against

Predicting, detecting and responding to outbreaks of known and emerging infectious diseases pose a worldwide problem, particularly in countries where the health system is fragile. In sub-Saharan Africa, outbreaks of established and emerging (e.g. Ebola) zoonotic diseases often have their origins in remote wilderness areas where pathogens circulate largely undetected between wild reservoir hosts and with few human cases. For reasons poorly understood, the transmission dynamics of these pathogens can change and outbreaks occur as the disease spills over into neighbouring populations of humans and livestock.Rhodesian Human African Trypanosomiasis (rHAT), caused by Trypanosoma brucei rhodesiense transmitted by tsetse flies, is a zoonotic disease associated with conservation areas of East and Southern Africa. In 2019-20, Malawi experienced a surge of rHAT cases. In a period of just three months, the number of cases was triple the annual mean for the previous decade, with most cases coming from communities located near two national parks. The underlying causes of the surge are uncertain but potential causes include changes in the ecology and behaviour of tsetse as a consequence of environmental changes, and/or the emergence of a virulent strain of Trypanosoma brucei rhodesiense. Currently, control of rHAT in Malawi relies largely on passive detection and treatment of cases. There are no vaccines or drugs to prevent rHAT and the only way of protecting people is by controlling tsetse flies, however, to do this across a national park is prohibitively expensive and logistically complex. More affordable and sustainable strategies which remove tsetse from settled areas and confine them to the park are needed.The overall goal of the STRESS-MALAWI project is to test the hypothesis that risk of rHAT for communities living on the edge of conservation areas can be reduced by focusing tsetse control efforts on the key ecological zones which sustain the tsetse populations biting humans. These zones are likely to be the edges of a conservation area where dense natural vegetation and an abundance of wild hosts sustain high numbers of tsetse relatively close to settlements.Focusing on the Vwaza Marsh Wildlife Reserve in northern Malawi, and the surrounding farming areas, we will undertake empirical and modelling studies to quantify the underlying spatial and temporal drivers of rHAT and identify potential causes of the 2019-surge in cases. Findings from these studies will allow us to design and deliver a cost-effective and spatially-informed tsetse control strategy in which insecticide-treated targets, which attract and kill tsetse, will be deployed to protect communities from rHAT. To achieve our goal, we will:-First, develop and implement a tsetse sampling strategy to quantify the population dynamics of tsetse and trypanosomes across the interface of conservation and agricultural areas. Tsetse will be sampled along transects across the interface and simultaneous mapping of landcover using satellite and drone imagery will quantify the relationship between tsetse abundance and vegetation.Second, quantify the numbers and type of tsetse attracted to humans moving outdoors and within buildings and hence identify where and when people are likely to be bitten.Third, determine whether the transmission potential of T. b. rhodesiense has increased due to the emergence of a new virulent strain of parasite.Finally, we will integrate knowledge from 1-3 to design and implement a vector control strategy at the interface of the Vwaza Marsh Reserve.Our findings will contribute to the development of a strategy for monitoring and control of rHAT in Malawi and other countries in East and Southern Africa. More generally, the data, models, trypanosome genomes and methods produced by our project will contribute to evidence-based strategies for controlling existing and emerging vector-borne zoonoses associated with wilderness areas.

预测、检测和应对已知和新出现的传染病的爆发是一个全球性问题，特别是在卫生系统脆弱的国家。在撒哈拉以南非洲，已确定的和新出现的人畜共患病（如埃博拉）的暴发往往起源于偏远的荒野地区，在那里，病原体在野生宿主之间传播，基本上未被发现，人间病例很少。由于尚不清楚的原因，这些病原体的传播动力学可能会发生变化，当疾病蔓延到邻近的人类和牲畜种群时，就会发生暴发。罗得西亚人非洲锥虫病（Rhodesian Human African Trypanosomelia，rHAT）由采采蝇传播的布氏锥虫引起，是一种与东非和南部非洲保护区有关的人畜共患疾病。在2019-20年，马拉维经历了rHAT病例的激增。在短短三个月的时间里，病例数量是前十年年均值的三倍，大多数病例来自两个国家公园附近的社区。这种激增的根本原因尚不确定，但可能的原因包括环境变化导致采采蝇的生态和行为发生变化，和/或布氏锥虫罗得西亚亚种的出现。目前，马拉维对rHAT的控制主要依赖于被动检测和病例治疗。没有疫苗或药物来预防rHAT，保护人们的唯一方法是控制采采蝇，然而，在国家公园内这样做是非常昂贵和后勤复杂的。更负担得起的和可持续的战略，从定居地区，并将其限制在park. STRESS-MALAWI项目的总体目标是测试的假设，即rHAT的风险，为社区生活在保护区的边缘，可以减少集中在关键生态区，维持采采蝇种群叮咬人类的采采蝇控制工作。这些区域很可能是保护区的边缘，在那里，密集的自然植被和丰富的野生宿主使大量采采蝇维持在相对靠近定居点的地方。我们将进行实证和建模研究，以量化rHAT的潜在空间和时间驱动因素，并确定2019年-案件激增。这些研究的结果将使我们能够设计和提供一个具有成本效益和空间信息的舌蝇控制策略，在该策略中，将部署吸引和杀死舌蝇的经处理的目标，以保护社区免受rHAT的侵害。为了达到我们的目标，我们将：-首先，制定和实施采采蝇抽样策略，以量化自然保护区和农业区交界处采采蝇和锥虫的种群动态。采蝇的样本将沿着整个界面的沿着样带进行采样，同时利用卫星和无人机图像绘制土地覆盖图，以量化采采蝇丰度与植被之间的关系。第二，量化吸引人们在户外和建筑物内移动的采采蝇的数量和类型，从而确定人们可能在何时何地被叮咬。B.最后，我们将整合1-3的知识，在Vwaza沼泽保护区的界面设计和实施一个媒介控制策略。我们的研究结果将有助于在马拉维和东非和南部非洲其他国家监测和控制rHAT的战略的发展。更一般地说，我们项目产生的数据，模型，锥虫基因组和方法将有助于控制与荒野地区相关的现有和新出现的媒介传播的人畜共患病的循证策略。