Operational accuracy and comparative persistent antigenicity of HRP2 rapid diagnostic tests for Plasmodium falciparum malaria in a hyperendemic region of Uganda.
Operational accuracy and comparative persistent antigenicity of HRP2 rapid diagnostic tests for Plasmodium falciparum malaria in a hyperendemic region of Uganda.
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DOI：
10.1186/1475-2875-7-221
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发表时间：
2008-10-29
期刊：
影响因子：
3
通讯作者：
Counihan H
中科院分区：
文献类型：
--
作者：
Kyabayinze DJ;Tibenderana JK;Odong GW;Rwakimari JB;Counihan H
通过显微镜对疟疾进行基于寄生虫的诊断需要实验室技能，而这些技能在外围卫生设施中通常是不具备的。快速诊断测试（RDTs）需要较少的专业知识，但在乌干达尚未充分评估在操作条件下的准确性。也有人担心RDT使用抗原富组氨酸蛋白2（HRP 2）来检测恶性疟原虫，因为这种抗原可以在有效治疗后持续存在，在没有感染的情况下给出假阳性检测结果。在乌干达的高流行区进行了疟疾Pf™免疫层析测试（ICT）的准确性评估和HRP 2 RDT的持续抗原性描述。采用横断面设计，共357名所有年龄段的发热患者进行了测试，使用ICT，并与显微镜作为金标准参考。两个独立的RDT读数用于评估准确性和观察者间的可靠性。采用纵向设计描述ICT和Paracheck的持续抗原性，224名6-59个月的儿童每隔7天随访一次，直到HRP 2抗原被RDTs检测不到。在横断面部分检测的357例患者中，40%（139例）的恶性疟原虫无性型血涂片呈阳性。ICT的总体敏感性为98%，特异性为72%，阴性预测值（NPV）为98%，阳性预测值（PPV）为69%。ICT在操作条件下显示出高的观察者间可靠性，95%的读数具有相同的结果（kappa统计值0.921，p < 0.001）。在成功的抗疟治疗后随访的儿童中，持续抗原性的平均持续时间为32天，并且该持续时间根据治疗前的寄生虫血症而显著变化。在寄生虫密度> 50，000/μl的患者中，持续抗原性的平均持续时间为37天，而寄生虫血症低于1，000/μl的患者为26天（对数秩21.9，p < 0.001）。信通技术是一种准确和适当的测试，可在没有显微镜的情况下用作诊断工具。然而，持续的抗原性降低了这种和其他基于HRP 2的RDT的准确性。特异性低仍然令人关切，特别是在5岁以下儿童中。这些都带来了需要考虑的局限性，例如它们用于诊断在治疗后两到四周内出现症状的患者。良好的临床技能对于解释测试结果至关重要。
Parasite-based diagnosis of malaria by microscopy requires laboratory skills that are generally unavailable at peripheral health facilities. Rapid diagnostic tests (RDTs) require less expertise, but accuracy under operational conditions has not been fully evaluated in Uganda. There are also concerns about RDTs that use the antigen histidine-rich protein 2 (HRP2) to detect Plasmodium falciparum, because this antigen can persist after effective treatment, giving false positive test results in the absence of infection. An assessment of the accuracy of Malaria Pf™ immuno-chromatographic test (ICT) and description of persistent antigenicity of HRP2 RDTs was undertaken in a hyperendemic area of Uganda. Using a cross-sectional design, a total of 357 febrile patients of all ages were tested using ICT, and compared to microscopy as the gold standard reference. Two independent RDT readings were used to assess accuracy and inter-observer reliability. With a longitudinal design to describe persistent antigenicity of ICT and Paracheck, 224 children aged 6–59 months were followed up at 7-day intervals until the HRP2 antigens where undetectable by the RDTs. Of the 357 patients tested during the cross-sectional component, 40% (139) had positive blood smears for asexual forms of P. falciparum. ICT had an overall sensitivity of 98%, a specificity of 72%, a negative predictive value (NPV) of 98% and a positive predictive value (PPV) of 69%. ICT showed a high inter-observer reliability under operational conditions, with 95% of readings having assigned the same results (kappa statistics 0.921, p < 0.001). In children followed up after successful antimalaria treatment, the mean duration of persistent antigenicity was 32 days, and this duration varied significantly depending on pre-treatment parasitaemia. In patients with parasite density >50,000/μl, the mean duration of persistent antigenicity was 37 days compared to 26 days for parasitaemia less than 1,000/μl (log rank 21.9, p < 0.001). ICT is an accurate and appropriate test for operational use as a diagnostic tool where microscopy is unavailable. However, persistent antigenicity reduces the accuracy of this and other HRP2-based RDTs. The low specificity continues to be of concern, especially in children below five years of age. These pose limitations that need consideration, such as their use for diagnosis of patients returning with symptoms within two to four weeks of treatment. Good clinical skills are essential to interpret test results.
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DOI：
10.1371/journal.pctr.0020020
发表时间：
2007-05-18
期刊：
PLoS clinical trials
影响因子：
--
作者：
Kamya, Moses R;Yeka, Adoke;Dorsey, Grant
通讯作者：
Dorsey, Grant
影响因子：
6.4
作者：
Hopkins, Heidi;Bebell, Lisa;Dorsey, Grant
通讯作者：
Dorsey, Grant
DOI：
10.4269/ajtmh.2002.66.379
发表时间：
2002-04-01
影响因子：
3.3
作者：
Coleman, RE;Maneechai, N;Sattabongkot, J
通讯作者：
Sattabongkot, J
影响因子：
--
作者：
Reyburn, Hugh;Mbakilwa, Hilda;Whitty, Christopher J. M.
通讯作者：
Whitty, Christopher J. M.
影响因子：
3.1
作者：
Carley, S;Dosman, S;Harrison, M
通讯作者：
Harrison, M