A comparison of three diagnostic techniques for malaria:: a rapid diagnostic test (NOW® Malaria), PCR and microscopy
A comparison of three diagnostic techniques for malaria:: a rapid diagnostic test (NOW® Malaria), PCR and microscopy
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DOI：
10.1179/136485907x156997
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发表时间：
2007-04-01
影响因子：
--
通讯作者：
Scaglia, M.
中科院分区：
文献类型：
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作者：
Gatti, S.;Gramegna, M.;Scaglia, M.
疟疾是热带流行地区常见的威胁生命的感染，也是大多数非流行国家实验室面临的诊断挑战。快速和准确的诊断是有效治疗的先决条件，特别是对于可能致命的恶性疟原虫感染病例。在目前的多中心研究中，将一种快速诊断检测（NOW Malaria）和几种商业化的基于pcr的检测方法（AMS61、AMS42、AMS43、AMS44和AMS45）的性能与血检显微镜检查的结果（目前的“金标准”）进行了比较。受试者为非欧洲移民（N=135）或国际旅行者（N=171）。各检测方法的结果一致性较好，kappa值均为>.8。虽然NOW疟疾快速检测在检测恶性疟原虫感染时敏感性（100%）和特异性（100%）均较高，但在检测其他疟原虫感染时特异性（93.1%）和敏感性（90.7%）较低。用于检测任何疟疾感染的AMS61检测结果与镜检结果基本一致（kappa=0.89），特异性为98.2%，敏感性为91.0%。虽然使用物种特异性分子引物鉴定恶性疟原虫和间日疟原虫的纯感染的结果与显微镜检查的结果很一致，但明显纯感染卵形疟原虫或疟疾疟原虫的受试者总是被发现pcr阴性。因此，与标准显微镜相比，NOW疟疾检测和基于pcr的检测在识别混合感染方面都很差。现在的疟疾检测和基于pcr的检测显然需要改进，特别是为了正确识别除恶性疟原虫以外的疟原虫感染，包括混合感染。目前，专家显微镜必须仍然是疟疾实验室诊断的主要手段。
Malaria is a common, life-threatening infection in endemic tropical areas and one that presents a diagnostic challenge to laboratories in most non-endemic countries. A rapid and accurate diagnosis is a prerequisite for effective treatment, especially for the potentially fatal cases of Plasmodium falciparum infection. In the present, multi-centre study, the performances of a rapid diagnostic test (NOW Malaria) and several, commercial, PCR-based assays (AMS61, AMS42, AMS43, AMS44 and AMS45) were compared against the results of microscopical examination of bloodsmears (the current 'gold standard'). The subjects were either non-European immigrants (N=135) or international travellers (N=171).There was good concordance between the results of all the detection methods, with kappa values of > 0.8. Although the NOW Malaria rapid test was both sensitive (100%) and specific (100%) in detecting P. falciparum infections, it was less specific (93.1%) and sensitive (90.7%) in identifying the other Plasmodium species.The results from the AMS61 assay, designed to detect any malarial infection, generally parallelled those of the microscopy (kappa=0.89), giving a specificity of 98.2% and a sensitivity of 91.0%. Although the use of species-specific molecular primers to identify pure infections with P. falciparum and P. vivax gave results that were in good agreement with those of the microscopy, the subjects who had apparently pure infections with P. ovale or P. malariae were always found PCR-negative. Compared with the standard microscopy, both the NOW Malaria test and the PCR-based assays were therefore poor at identifying mixed infections.The NOW Malaria test and the PCR-based assays clearly need to be improved, particularly for the correct identification of infections with Plasmodium spp. other than P. falciparum, including mixed infections. For now, expert microscopy must remain the mainstay of the laboratory diagnosis of malaria.