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

基本信息

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
项目类别：
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

项目摘要

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两个邻国进行比较。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) 干预后六个月内疟疾发病率的科学目标是基于这些结果。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播环境我们的前提是干预措施将减少寄生虫。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，传播水平相对较低。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严重洪水后，我们将开展集群性应用，以减少恶性疟疾的发病率。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家庭空间（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，我们将对成人和青少年进行每周监测。哨点家庭和家庭周围空间内的按蚊将被收集。计数、鉴定物种并测试恶性疟原虫子孢子的存在。假设：洪水。将创造无数受冈比亚按蚊复合体青睐的小池，从而导致冈比亚按蚊的优势。 s.s. 具有阿拉伯按蚊作为广泛使用 LLIN 的重要载体的潜力。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）我们将进行基线和定量纵向分析。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费用。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。