Abstract

Background

Determining malaria transmission within regions of low, heterogenous prevalence is difficult. A variety of malaria tests exist and range from identification of diagnostic infection to testing for prior exposure. This study describes the concordance of multiple malaria tests using data from a 2015 household survey conducted in Ethiopia.

Methods

Blood samples (n=2279) from 3 regions in northern Ethiopia were assessed for Plasmodium falciparum and Plasmodium vivax by means of microscopy, rapid diagnostic test, multiplex antigen assay, and multiplex assay for immunoglobulin G (IgG) antibodies. Geospatial analysis was conducted with spatial scan statistics and kernel density estimation to identify malaria hot spots by different test results.

Results

The prevalence of malaria infection was low (1.4% by rapid diagnostic test, 1.0% by microscopy, and 1.8% by laboratory antigen assay). For P. falciparum, overlapping spatial clusters for all tests and an additional 5 unique IgG clusters were identified. For P. vivax, clusters identified with bead antigen assay, microscopy, and IgG partially overlapped.

Conclusions

Assessing the spatial distribution of malaria exposure using multiple metrics can improve the understanding of malaria transmission dynamics in a region. The relative abundance of antibody clusters indicates that in areas of low transmission, IgG antibodies are a more useful marker to assess malaria exposure.

中文翻译：

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通过显微镜、快速诊断测试、实验室抗体和抗原数据对埃塞俄比亚北部恶性疟原虫和间日疟原虫的空间分布进行分析

摘要

背景

确定疟疾在低、异质流行地区的传播是困难的。存在多种疟疾测试，范围从诊断感染的识别到先前暴露的测试。本研究使用 2015 年在埃塞俄比亚进行的家庭调查数据，描述了多项疟疾检测的一致性。

方法

通过显微镜检查、快速诊断测试、多重抗原测定和免疫球蛋白 G (IgG) 抗体多重测定，对来自埃塞俄比亚北部 3 个地区的血液样本 (n=2279) 进行了恶性疟原虫和间日疟原虫的评估。使用空间扫描统计和核密度估计进行地理空间分析，以通过不同的测试结果识别疟疾热点。

结果

疟疾感染率较低（快速诊断检测为 1.4%，显微镜检测为 1.0%，实验室抗原检测为 1.8%）。对于恶性疟原虫，确定了所有测试的重叠空间簇和另外 5 个独特的 IgG 簇。对于间日疟原虫，用珠子抗原测定、显微镜检查和 IgG 鉴定的簇部分重叠。

结论

使用多个指标评估疟疾暴露的空间分布可以提高对一个地区疟疾传播动态的理解。抗体簇的相对丰度表明，在低传播区域，IgG 抗体是评估疟疾暴露的更有用的标志物。