Evaluation of light microscopy and rapid diagnostic test for the detection of malaria under operational field conditions: a household survey in Ethiopia
Evaluation of light microscopy and rapid diagnostic test for the detection of malaria under operational field conditions: a household survey in Ethiopia
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DOI：
10.1186/1475-2875-7-118
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发表时间：
2008-07-03
期刊：
影响因子：
3
通讯作者：
Richards, Frank O.
中科院分区：
文献类型：
--
作者：
Endeshaw, Tekola;Gebre, Teshome;Richards, Frank O.
背景资料：在大多数资源贫乏的环境中，疟疾的诊断通常是基于临床体征和症状，而不是通过使用显微镜或快速诊断测试（RDT）检测血液中的寄生虫。在以人口为基础的疟疾调查中，准确的诊断很重要：显微镜检查是金标准，而快速诊断技术可以立即发现和治疗。RDT和显微镜检查在低或不稳定的传播区域的一致性尚未评估Objective.Objectives：本研究旨在使用显微镜检查和RDT，评估埃塞俄比亚Amhara、Oromia和南部民族、民族和人民（SNNP）地区疟疾流行区的疟疾寄生虫患病率，并调查田间条件下显微镜检查和RDT之间的一致性。2006年12月至2007年2月期间，在阿姆哈拉、奥罗莫和南部各州、民族和人民地区随机选择的224个群组中进行了一项基于人口的调查，每个群组有25个家庭。使用两种方法对居住在偶数家庭的所有人的手指采血样本进行检测：Giemsa染色血玻片的光学显微镜;和RDT（Pan/Pf的ParaScreen设备）。结果：共有13，960人符合疟原虫检测条件，其中11，504人（82%）被纳入分析。总体玻片阳性率为4.1%（95%置信区间[ CI] 3.4 - 5.0%），而ParaScreen RDT在3.3%（95% CI 2.6 - 4.1%）的受试者中呈阳性。考虑到显微镜检查为金标准，ParaScreen RDT表现出高度特异性（98.5%; 95% CI 98.3 - 98.7）和中度敏感性（47.5%; 95%CI 42.8 - 52.2），阳性预测值为56.8%结论：血涂片镜检法仍是以人群为基础的疟疾寄生虫病流行率调查的首选方法。显微镜和RDT之间的协议水平，保证在不同的传输设置和临床情况下进一步调查。
Background: In most resource-poor settings, malaria is usually diagnosed based on clinical signs and symptoms and not by detection of parasites in the blood using microscopy or rapid diagnostic tests (RDT). In population-based malaria surveys, accurate diagnosis is important: microscopy provides the gold standard, whilst RDTs allow immediate findings and treatment. The concordance between RDTs and microscopy in low or unstable transmission areas has not been evaluated.Objectives: This study aimed to estimate the prevalence of malaria parasites in randomly selected malarious areas of Amhara, Oromia, and Southern Nations, Nationalities and Peoples' (SNNP) regions of Ethiopia, using microscopy and RDT, and to investigate the agreement between microscopy and RDT under field conditions.Methods: A population-based survey was conducted in 224 randomly selected clusters of 25 households each in Amhara, Oromia and SNNP regions, between December 2006 and February 2007. Fingerpick blood samples from all persons living in even-numbered households were tested using two methods: light microscopy of Giemsa-stained blood slides; and RDT (ParaScreen device for Pan/Pf).Results: A total of 13,960 people were eligible for malaria parasite testing of whom 11,504 (82%) were included in the analysis. Overall slide positivity rate was 4.1% (95% confidence interval [ CI] 3.4 -5.0%) while ParaScreen RDT was positive in 3.3% (95% CI 2.6 -4.1%) of those tested. Considering microscopy as the gold standard, ParaScreen RDT exhibited high specificity (98.5%; 95% CI 98.3 -98.7) and moderate sensitivity (47.5%; 95% CI 42.8 -52.2) with a positive predictive value of 56.8% ( 95% CI 51.7 - 61.9) and negative predictive value of 97.6% ( 95% CI 97.6 - 98.1%) under field conditions.Conclusion: Blood slide microscopy remains the preferred option for population-based prevalence surveys of malaria parasitaemia. The level of agreement between microscopy and RDT warrants further investigation in different transmission settings and in the clinical situation.