Ethiopian Health & Nutrition Research Institute, PO Box 1242, Addis Ababa, Ethiopia.
Malar J. 2013 Jun 27;12:218. doi: 10.1186/1475-2875-12-218.
Malaria is a major public health problem in Ethiopia. Plasmodium falciparum and Plasmodium vivax co-exist and malaria rapid diagnostic test (RDTs) is vital in rendering parasite-confirmed treatment especially in areas where microscopy from 2008 to 2010 is not available. CareStartTM Malaria Pf/Pv combo test was evaluated compared to microscopy in Butajira area, south-central Ethiopia. This RDT detects histidine-rich protein-2 (HRP2) found in P. falciparum, and Plasmodium enzyme lactate dehydrogenase (pLDH) for diagnosis of P. vivax. The standard for the reporting of diagnostic accuracy studies was complied. Among 2,394 participants enrolled, 10.9% (n=87) were Plasmodium infected (household survey) and 24.5% (n=392) health facility-based using microscopy. In the household surveys, the highest positivity was caused by P. vivax (83.9%, n=73), P. falciparum (15.0%, n=13), and the rest due to mixed infections of both (1.1%, n=1). In health facility, P. vivax caused 78.6% (n=308), P. falciparum caused 20.4% (n=80), and the rest caused by mixed infections 1.0% (n=4). RDT missed 9.1% (n=8) in household and 4.3% (n=17) in health facility-based surveys among Plasmodium positive confirmed by microscopy while 3.3% (n=24) in household and 17.2% (n=208) in health facility-based surveys were detected false positive. RDT showed agreement with microscopy in detecting 79 positives in household surveys (n=796) and 375 positives in health centre survey (n=1,598).RDT performance varied in both survey settings, lowest PPV (64.3%) for Plasmodium and P. falciparum (77.2%) in health centres; and Plasmodium (76.7%) and P. falciparum (87.5%) in household surveys. NPV was low in P. vivax in health centres (77.2%) and household (87.5%) surveys. Seasonally varying RDT precision of as low as 14.3% PPV (Dec. 2009), and 38.5% NPV (Nov. 2008) in health centre surveys; and 40-63.6% PPV was observed in household surveys. But the influence of age and parasite density on RDT performance was not ascertained. Establishing quality control of malaria RDT in the health system in areas with low endemic and where P. falciparum and P. vivax co-exist is recommendable. CareStartTM RDT might be employed for epidemiological studies that require interpreting the results cautiously. Future RDT field evaluation against microscopy should be PCR corrected.
疟疾是埃塞俄比亚的一个主要公共卫生问题。恶性疟原虫和间日疟原虫共存，疟疾快速诊断检测（RDT）对于提供寄生虫确认的治疗至关重要，特别是在 2008 年至 2010 年无法进行显微镜检查的地区。在埃塞俄比亚中南部的布塔吉拉地区，对 CareStartTM 疟原虫 Pf/Pv 组合检测进行了评估，与显微镜检查进行了比较。该 RDT 检测恶性疟原虫中存在的组氨酸丰富蛋白-2（HRP2），以及用于诊断间日疟原虫的疟原虫酶乳酸脱氢酶（pLDH）。报告诊断准确性研究的标准得到了遵守。在纳入的 2394 名参与者中，10.9%（n=87）为疟原虫感染（家庭调查），24.5%（n=392）为使用显微镜的医疗机构调查。在家庭调查中，阳性率最高的是间日疟原虫（83.9%，n=73），恶性疟原虫（15.0%，n=13），其余为两者的混合感染（1.1%，n=1）。在医疗机构中，间日疟原虫引起 78.6%（n=308），恶性疟原虫引起 20.4%（n=80），其余由混合感染引起 1.0%（n=4）。在家庭调查中，RDT 在显微镜确认的疟原虫阳性中漏检了 9.1%（n=8），在医疗机构调查中漏检了 4.3%（n=17），而在家庭调查中假阳性检测率为 3.3%（n=24），在医疗机构调查中假阳性检测率为 17.2%（n=208）。RDT 在检测家庭调查中的 79 个阳性病例（n=796）和卫生中心调查中的 375 个阳性病例（n=1,598）方面与显微镜具有一致性。RDT 在两种调查环境中的性能均存在差异，在卫生中心，对疟原虫和恶性疟原虫的最高阳性预测值（PPV）为 64.3%和 77.2%；在家庭调查中，对疟原虫和恶性疟原虫的最高阳性预测值分别为 76.7%和 87.5%。在卫生中心和家庭调查中，间日疟原虫的阴性预测值（NPV）均较低，分别为 77.2%和 87.5%。在卫生中心的调查中，RDT 的精度在季节性上有低至 14.3%的阳性预测值（2009 年 12 月）和 38.5%的阴性预测值（2008 年 11 月）；而在家庭调查中观察到 40-63.6%的阳性预测值。但是，年龄和寄生虫密度对 RDT 性能的影响尚未确定。建议在寄生虫低流行地区和恶性疟原虫与间日疟原虫共存地区建立疟疾 RDT 的质量控制。CareStartTM RDT 可用于需要谨慎解释结果的流行病学研究。未来应使用聚合酶链反应（PCR）校正方法对 RDT 进行现场评估。
