Establishing the Feasibility of using daily Dried Blood Spots (DBS) to study the Natural History of Low-density Asymptomatic Malaria Infection to Inform Malaria Elimination

摘要 在地方性人群中有相当数量的低密度疟原虫感染， 这类感染的比例似乎随着传播强度的降低而增加。但大多数 迄今为止的研究已经在单个时间点或不常见的时间点评估了这些感染， 关于这些感染的动态及其对疟疾的可能贡献的信息很少或没有 传输最近的数据表明，无症状的寄生虫密度可能比 以前知道的。本项目的目标是论证日干血斑的可行性和质量 (DBS)采样，以量化低密度无症状的寄生虫和配子体密度动力学 恶性疟原虫感染，以更好地了解其对疟疾传播的可能贡献， 在经历中间传播的人群中研究这种感染的自然史。我们将 测量在28天内成功收集每日DBS的受试者比例，并量化 随着时间的推移收集的样品的质量。超灵敏定量逆转录PCR检测P. 将恶性疟原虫18S rRNA和配子体mRNA结合起来，以经济有效地识别受感染的参与者 然后解卷积每日样本以说明寄生虫密度动力学。如果成功， 本研究为进一步研究低密度寄生虫携带动力学提供了技术手段， 可推广到面临无症状疟疾患者公共卫生问题的其他疟疾流行国家 为控制和消除疟疾而努力。

ABSTRACT There are a significant number of low-density Plasmodium infections in endemic populations, and the proportion of this type of infection appears to increase with decreasing transmission intensity. However, most studies to date have assessed these infections at a single time point or at infrequent time points, which offers little to no information on the dynamics of these infections and their possible contribution to malaria transmission. Recent data suggest that asymptomatic parasite densities may be much more dynamic than previously known. The goal of this project is to demonstrate the feasibility and quality of daily dried blood spot (DBS) sampling in order to quantify parasite and gametocyte density kinetics of low-density asymptomatic Plasmodium falciparum infections to better understand their possible contribution to malaria transmission by studying the natural history of such infections in a population experiencing intermediate transmission. We will measure the proportion of subjects who successfully collect daily DBS over a 28-day period, and quantify the quality of the samples collected over time. Ultrasensitive quantitative reverse transcription PCR for P. falciparum 18S rRNA and gametocyte mRNA will be combined to cost-effectively identify infected participants and then deconvolute daily samples to illustrate the parasite density kinetics. If successful, the results from this study will offer a technique to further study the dynamics of low-density parasite carriage and be generalizable to other malaria-endemic countries confronting the public health problem of asymptomatic malaria for malaria control and elimination.