Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK.
Malar J. 2021 Sep 17;20(1):373. doi: 10.1186/s12936-021-03908-7.
A key step to advancing the goal of malaria elimination in Viet Nam by 2030 is focusing limited resources for treatment and prevention to groups most at risk for malaria transmission.
To better understand risk factors for malaria transmission in central Viet Nam, a survey of 1000 malaria positive cases and 1000 malaria negative controls was conducted. Cases and controls were matched for age and gender and self-presented at commune health stations (CHS) in Binh Phuoc, Dak Nong and Dak Lak Provinces. Diagnoses were confirmed with microscopy, rapid diagnostic test and PCR. Participants were interviewed about 50 potential risk factors for malaria, which included information about occupation, forest visitation, travel, healthcare-seeking behaviour and prior use of anti-malaria interventions. Participants were enrolled by trained government health workers and the samples were analysed in Vietnamese government laboratories. Data were analysed by univariable, block-wise and multivariable logistic regression.
Among cases, 61.8% had Plasmodium falciparum, 35.2% Plasmodium vivax and 3% mixed species infections. Median (IQR) age was 27 (21-36) years and 91.2% were male. Twenty-five risk factors were associated with being a case and eleven with being a control. Multivariable analysis found that malaria cases correlated with forest workers, recent forest visitation, longer duration of illness, having a recorded fever, number of malaria infections in the past year, having had prior malaria treatment and having previously visited a clinic.
This study demonstrates the benefits of increased statistical power from matched controls in malaria surveillance studies, which allows identification of additional independent risk factors. It also illustrates an example of research partnership between academia and government to collect high quality data relevant to planning malaria elimination activities. Modifiable risk factors and implications of the findings for malaria elimination strategy are presented.
通过集中有限的资源用于治疗和预防最容易感染疟疾的人群，越南推进 2030 年消除疟疾目标的关键步骤。
为了更好地了解越南中部疟疾传播的风险因素，对 1000 例疟疾病例和 1000 例疟阴性对照进行了调查。病例和对照按年龄和性别匹配，并在平定、得农和得乐省的社区卫生站就诊。通过显微镜检查、快速诊断测试和 PCR 确认诊断。对参与者进行了约 50 个潜在疟疾风险因素的访谈，包括职业、森林访问、旅行、医疗保健寻求行为和以前使用抗疟干预措施的信息。参与者由经过培训的政府卫生工作者招募，样本在越南政府实验室进行分析。数据采用单变量、块式和多变量逻辑回归进行分析。
在病例中，61.8%为恶性疟原虫，35.2%为间日疟原虫，3%为混合物种感染。中位数（IQR）年龄为 27（21-36）岁，91.2%为男性。25 个危险因素与病例有关，11 个与对照有关。多变量分析发现，疟疾病例与森林工人、最近的森林访问、更长的疾病持续时间、有记录的发热、过去一年的疟疾感染次数、有过疟疾治疗史和以前去过诊所有关。
本研究表明，匹配对照增加了疟疾监测研究的统计能力，从而能够确定更多的独立风险因素。它还说明了学术界和政府之间合作收集与规划消除疟疾活动相关的高质量数据的研究伙伴关系的一个例子。提出了可改变的风险因素和研究结果对消除疟疾战略的影响。
