<p>Index case data file.</p>

Reactive case detection (RACD), or testing and treatment of close contacts of recent malaria cases, is widely used in settings nearing malaria elimination, but often results in very low yield and uncertain impact. In areas where the primary vector exposure occurs outside the home, adapting RACD to target high-risk populations with specific exposure profiles may increase yield, surveillance value, and impact on treatment rates and transmission. We evaluated the feasibility and yield of a risk-based RACD approach based upon forest-based exposure, in comparison with the standard neighborhood and household-based RACD conducted in Aceh Province, Indonesia. Index malaria cases were enrolled from public health facilities in five subdistricts. For each index case, standard RACD included testing members of households within 500 m, while risk-based RACD involved testing non-household contacts sharing a forest worksite or forest travel. Infection prevalence was measured by light microscopy, loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR). The study enrolled 47 index malaria cases during the study period, the majority (28) of which were diagnosed as P. knowlesi infections. Forty-one of the cases reported potential forest exposure outside the home, and follow-up was completed for 40 cases. Standard household-based RACD tested 847 household members from 34 index cases, yielding only 1 infection by LAMP/PCR (0.1%; 95% Confidence Interval (CI) 0.0 – 0.7%). Risk-based RACD tested 179 eligible contacts from 32 index cases, yielding 8 LAMP positive infections (4.5%; 95% CI 1.9 – 8.6%), including 3 confirmed by PCR (1.7%; 95% CI 0.3 – 4.8%). In Aceh Province, targeting RACD to non-household contacts with shared high-risk exposures substantially increased infection yield compared to household-based RACD. Risk-based, exposure-driven approaches may improve the effectiveness of RACD in settings where malaria risk is greater outside the home.反应性病例检测（Reactive case detection, RACD），即针对近期疟疾病例的密切接触者开展检测与治疗，已在接近疟疾消除的地区得到广泛应用，但往往检出率偏低且干预效果尚不明确。在主要疟媒叮咬暴露发生于住宅外的区域，若将RACD策略调整为针对具有特定暴露特征的高风险人群实施，或可提升检出率、监测价值，以及对治疗率和疟疾传播的干预效果。本研究针对基于森林暴露的风险导向型RACD方案的可行性与检出率进行了评估，并与印度尼西亚亚齐省实施的标准家庭与社区为基础的RACD方案展开对照研究。索引疟疾病例从5个分区的公共卫生机构招募。对于每一例索引病例，标准RACD方案会对500米范围内的家庭住户成员进行检测，而风险导向型RACD则会对共享森林作业场所或共同参与森林出行的非家庭接触者开展检测。感染患病率通过光学显微镜、环介导等温扩增（loop-mediated isothermal amplification, LAMP）及聚合酶链式反应（polymerase chain reaction, PCR）进行检测。研究周期内共纳入47例索引疟疾病例，其中多数（28例）被诊断为诺氏疟原虫（P. knowlesi）感染。41例病例报告了住宅外的潜在森林暴露史，最终完成40例病例的随访工作。标准家庭型RACD共为34例索引病例检测了847名家庭成员，仅通过LAMP/PCR检出1例感染（0.1%；95%置信区间（Confidence Interval, CI）0.0 – 0.7%）。风险导向型RACD为32例索引病例检测了179名符合条件的接触者，检出8例LAMP阳性感染者（4.5%；95% CI 1.9 – 8.6%），其中3例经PCR确认（1.7%；95% CI 0.3 – 4.8%）。在亚齐省，相较于家庭型RACD，将RACD靶向针对存在共同高风险暴露史的非家庭接触者，可大幅提升感染检出率。在住宅外疟疾风险更高的地区，基于暴露风险的导向型干预方案或可改善RACD的实施效果。