莫桑比克南部超敏和常规疟疾快速诊断检测的现场性能。
Field performance of ultrasensitive and conventional malaria rapid diagnostic tests in southern Mozambique.
机构信息
ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
出版信息
Malar J. 2020 Dec 7;19(1):451. doi: 10.1186/s12936-020-03526-9.
BACKGROUND
An ultrasensitive malaria rapid diagnostic test (RDT) was recently developed for the improved detection of low-density Plasmodium falciparum infections. This study aimed to compare the diagnostic performance of the PfHRP2-based Abbott Malaria Ag P. falciparum ultrasensitive RDT (uRDT) to that of the conventional SD-Bioline Malaria Ag P. falciparum RDT (cRDT) when performed under field conditions.
METHODS
Finger-prick blood samples were collected from adults and children in two cross-sectional surveys in May of 2017 in southern Mozambique. Using real-time quantitative PCR (RT-qPCR) as the reference method, the age-specific diagnostic performance indicators of the cRDT and uRDT were compared. The presence of histidine-rich protein 2 (HRP2) and Plasmodium lactate dehydrogenase (pLDH) antigens was evaluated in a subset from dried blood spots by a quantitative antigen assay. pfhrp2 and pfhrp3 gene deletions were assessed in samples positive by RT-qPCR and negative by both RDTs.
RESULTS
Among the 4,396 participants with complete test results, the sensitivity of uRDTs (68.2; 95% CI 60.8 to 74.9) was marginally better than that of cRDTs (61.5; 95% CI 53.9 to 68.6) (p-value = 0.004), while the specificities were similar (uRDT: 99.0 [95% CI 98.6 to 99.2], cRDT: 99.2 [95% CI 98.9 to 99.4], p-value = 0.02). While the performance of both RDTs was lowest in ≥ 15-year-olds, driven by the higher prevalence of low parasite density infections in this group, the sensitivity of uRDTs was significantly higher in this age group (54.9, 95% CI 40.3 to 68.9) compared to the sensitivity of cRDTs (39.2, 95% CI 25.8 to 53.9) (p-value = 0.008). Both RDTs detected P. falciparum infections at similar geometric mean parasite densities (112.9 parasites/μL for uRDTs and 145.5 parasites/μL for cRDTs). The presence of HRP2 antigen was similar among false positive (FP) samples of both tests (80.5% among uRDT-FPs and 84.4% among cRDT-FPs). Only one false negative sample was detected with a partial pfhrp2 deletion.
CONCLUSION
This study showed that the uRDTs developed by Abbott do not substantially outperform SD-Bioline Pf malaria RDTs in the community and are still not comparable to molecular methods to detect P. falciparum infections in this study setting.
背景
最近开发了一种超灵敏的疟疾快速诊断检测（RDT），用于提高对低密度疟原虫感染的检测能力。本研究旨在比较基于 PfHRP2 的 Abbott 疟疾 Ag P. falciparum 超灵敏 RDT（uRDT）与传统 SD-Bioline 疟疾 Ag P. falciparum RDT（cRDT）在现场条件下的诊断性能。
方法
2017 年 5 月，在莫桑比克南部进行了两项横断面研究，采集成人和儿童的指血样。以实时定量 PCR（RT-qPCR）为参考方法，比较了 cRDT 和 uRDT 的年龄特异性诊断性能指标。通过定量抗原检测评估了一部分干血斑中存在的组氨酸丰富蛋白 2（HRP2）和疟原虫乳酸脱氢酶（pLDH）抗原。在 RT-qPCR 阳性且两种 RDT 均阴性的样本中评估了 pfhrp2 和 pfhrp3 基因缺失。
结果
在 4396 名具有完整检测结果的参与者中，uRDT 的敏感性（68.2%，95%CI 60.8 至 74.9）略高于 cRDT（61.5%，95%CI 53.9 至 68.6）（p 值=0.004），而特异性相似（uRDT：99.0%，95%CI 98.6%至 99.2%，cRDT：99.2%，95%CI 98.9%至 99.4%，p 值=0.02）。尽管两种 RDT 的性能在≥15 岁的人群中均最低，这主要是由于该人群中低寄生虫密度感染的患病率较高，但 uRDT 的敏感性在该年龄组中明显更高（54.9%，95%CI 40.3%至 68.9%），高于 cRDT（39.2%，95%CI 25.8%至 53.9%）（p 值=0.008）。两种 RDT 在相似的几何平均寄生虫密度下检测到疟原虫感染（uRDT 为 112.9 个寄生虫/μL，cRDT 为 145.5 个寄生虫/μL）。两种测试的假阳性（FP）样本中 HRP2 抗原的存在情况相似（uRDT-FP 中为 80.5%，cRDT-FP 中为 84.4%）。仅检测到一个具有部分 pfhrp2 缺失的假阴性样本。
结论
本研究表明， Abbott 开发的 uRDT 并未在社区中显著优于 SD-Bioline Pf 疟疾 RDT，并且在本研究环境中仍然无法与分子方法相比，用于检测疟原虫感染。
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