After the flood: Optimal strategies to prevent malaria epidemics caused by severe flooding

洪水过后：预防严重洪水引起的疟疾流行的最佳策略

• 批准号: 10803934
• 负责人: Ross Mathew Boyce
• 金额: $ 99.8万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-08 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10803934
• 关键词: 12 year old; Acute; Address; Adolescent; Adult; Affect; Anopheles Genus; Anxiety; Area; Artemisinins; Automobile Driving; Binding; Biological Factors; Blood; Chemoprevention; Child; Cluster randomized trial; Collaborations; Communities; Complex; Cost Effectiveness Analysis; Culicidae; Data; Dedications; Development; Droughts; Economic Burden; Economics; Environment; Epidemic; Evolution; Expenditure; Falciparum Malaria; Feeding behaviors; Floods; Frequencies; Goals; Habitats; Health; Health care facility; Healthcare; Hospitalization; Household; Human; Incidence; Income; Intervention; Knowledge; Laboratories; Malaria; Mental Health; National Institute of Allergy and Infectious Disease; Parasites; Personal Satisfaction; Phase; Plasmodium falciparum; Population; Public Health; Research; Resistance; Rural; Sampling; Schools; Scientist; Seasons; Sentinel; Site; Social Impacts; Social outcome; Source; Sporozoites; Surface; Surveys; Temperature; Testing; Time; Training; Uganda; United States National Institutes of Health; Vector-transmitted infectious disease; Work; arm; burden of illness; climate change; climate impact; comparison control; cost effectiveness; economic impact; economic outcome; effectiveness evaluation; extreme weather; feeding; health economics; malaria transmission; new epidemic; post intervention; prevent; preventive intervention; primary outcome; relative cost; social factors; socioeconomics; tool; transmission process; uptake; vector

PROJECT SUMMARY/ABSTRACT The impact of climate change, including the increased frequency of weather extremes such as flooding, on the incidence of malaria and other vector-borne diseases is an issue of substantial public health importance. Therefore, there is an urgent need to develop effective mitigation and control strategies. In May 2020, we piloted a post-flood malaria chemoprevention intervention in rural western Uganda. When compared to two neighboring villages where no intervention was deployed, we estimated a 53% reduction (aRR 0.47, 95% CI 0.34 – 0.62, p<.01) in malaria incidence in the six months post-intervention. Building on these results, the scientific aim of this proposal is to evaluate the effectiveness of a targeted, time-limited malaria chemoprevention intervention with and without larval source management (LSM) to reduce excess disease burden in a perennial, high- transmission setting following severe flooding. Our premise is that the intervention will reduce the parasite reservoir during the critical “rebound” period, when vectors are re-establishing habitats thereby maintaining relatively low levels of transmission until conditions have returned to the pre-flood baseline. Specifically, we will: Aim 1: Determine the effectiveness of chemoprevention with or without peri-domestic larvicide application to reduce the incidence of P. falciparum malaria after severe flooding. We will conduct a cluster randomized trial in 50 villages (144 clusters) in rural western Uganda, where flooding relatively predictable, to compare: (i) LLIN distribution (control), (ii) LLIN distribution plus three, monthly rounds of DP provided to children ≤12 years of age (DP), and (iii) LLIN+DP with three months of bi-weekly application of larvicide in the peri- domestic space (DP+Bti). Hypothesis: Chemoprevention will achieve a sustained (≥6 months) reduction in malaria incidence of ≥30% compared to the control arm without the emergence of artemisinin resistance. Aim 2: Elucidate the evolution of vector populations, feeding behaviors, and sporozoite rate in affected villages up to one year after flooding. We will perform weekly surveillance for adult and juvenile Anopheles mosquitoes in sentinel households and within the peri-domestic space. Collected mosquitoes will be counted, and identified to species and tested for the presence of P. falciparum sporozoites. Hypothesis: Flooding will create innumerable small pools favored by An. gambiae complex resulting in predominance of An. gambiae s.s. with potential for emergence of An. arabiensis as important vector in setting of widespread LLIN use.23 Aim 3: Evaluate the relative cost-effectiveness of chemoprevention (Aim 3A) and assess social and economic impacts on households (Aim 3B). We will conduct baseline and longitudinal quantitative surveys in sample clusters to evaluate impacts of the interventions on (i) economic activities and income, (ii) health seeking and expenditures, and (iii) mental health and well-being. These data will inform a cost effectiveness analysis of chemoprevention compared to the control (i.e., relative cost per case averted). Hypothesis: Chemoprevention will mitigate negative effects of malaria in the aftermath of a flood.

项目概要/摘要 气候变化的影响，包括洪水等极端天气频率的增加， 疟疾和其他媒介传播疾病的发病率是一个具有重大公共卫生重要性的问题。 因此，迫切需要制定有效的缓解和控制策略。 2020年5月，我们进行了试点 乌干达西部农村地区的洪水后疟疾化学预防干预措施。与相邻的两个相比 对于未采取干预措施的村庄，我们估计减少了 53%（aRR 0.47，95% CI 0.34 – 0.62， p<.01) 干预后六个月的疟疾发病率。基于这些结果，科学目标 该提案旨在评估有针对性的、有时限的疟疾化学预防干预措施的有效性 有或没有幼虫源管理（LSM），以减少多年生、高死亡率的过度疾病负担 严重洪水后的传输设置。我们的前提是干预将减少寄生虫 在关键的“反弹”时期，媒介正在重新建立栖息地，从而维持水库 在情况恢复到洪水前的基线之前，传输水平相对较低。具体来说，我们将： 目标 1：确定使用或不使用围内杀幼虫剂的化学预防的有效性 应用以减少严重洪水后恶性疟疾的发病率。我们将进行集群 在乌干达西部农村地区的 50 个村庄（144 个集群）进行的随机试验，这些地方的洪水相对可预测 比较：(i) LLIN 分布（对照），(ii) LLIN 分布加上每月向儿童提供三轮 DP ≤ 12 岁 (DP)，以及 (iii) LLIN+DP，在围产期每两周使用杀幼虫剂三个月 国内空间（DP+Bti）。假设：化学预防将实现持续（≥6 个月）的减少 与未出现青蒿素耐药性的对照组相比，疟疾发病率≥30%。 目标 2：阐明媒介种群的进化、摄食行为和子孢子率 洪水发生后一年内受影响的村庄。我们将每周对成人和青少年进行监测 哨点家庭和家庭周围空间内的按蚊。收集到的蚊子将 计数、鉴定物种并测试恶性疟原虫子孢子的存在。假设：洪水 将创造出无数安所青睐的小池子。冈比亚复合体导致安的优势。冈比亚 s.s.具有出现 An 的潜力。 arabiensis 是广泛使用 LLIN 的重要载体23 目标 3：评估化学预防的相对成本效益（目标 3A）并评估社会效益 对家庭的经济影响（目标 3B）。我们将进行基线和纵向定量 对样本组进行调查，以评估干预措施对 (i) 经济活动和收入，(ii) 的影响 寻求健康和支出，以及 (iii) 心理健康和福祉。这些数据将告知成本 与对照相比化学预防的有效性分析（即避免每个病例的相对成本）。 假设：化学预防将减轻洪水后疟疾的负面影响。