Oguonu Tagbo, Shu Elvis, Ezeonwu Bertilla U, Lige Bao, Derrick Anne, Umeh Rich E, Agbo Eddy
Department of Pediatrics, University of Nigeria Teaching Hospital, Enugu, Nigeria.
Malar J. 2014 Oct 15;13:403. doi: 10.1186/1475-2875-13-403.
Accurate rapid diagnosis is one of the important steps in the effort to reduce morbidity and mortality of malaria. Blood-specific malaria rapid diagnostic tests (RDTs) are currently in use but other body fluid specific diagnostic test kits are being developed. The aim of the present study was to evaluate the performance characteristics of a one-step Urine Malaria Test™ (UMT) dipstick in detecting Plasmodium falciparum HRP2, a poly-histidine antigen in urine of febrile patients for malaria diagnosis.
This was an observational study in which a urine-based malaria test kit was used in malaria diagnosis in a normal field setting. Two hundred and three individuals who presented with fever (≥37.5°C) at seven outpatient clinics in Enugu State during periods of high and low transmission seasons in Southeastern Nigeria were enrolled. Matched samples of urine and blood of consecutively enrolled subjects were tested with UMT and blood smear microscopy.
With the blood smear microscopy as standard, the disease prevalence was 41.2% and sensitivity for the UMT was 83.75% (CI: 73.81 to 91.95%, Kappa 0.665, p =0.001). The UMT had an LLD of 120 parasites/μl but the sensitivity at parasite density less than ≤200 parasites/μl was 50% and 89.71% at density ≥201 parasites/μl with specificity of 83.48%. The positive and negative predictive values were 77.91% and 88.07%, respectively.
The UMT showed moderate level of sensitivity compared with blood smear microscopy. The test kit requires further improvement on its sensitivity in order to be deployable for field use in malaria endemic regions.
准确快速诊断是降低疟疾发病率和死亡率的重要步骤之一。目前正在使用血液特异性疟疾快速诊断检测(RDT),但其他体液特异性诊断试剂盒也在研发中。本研究的目的是评估一步式尿液疟疾检测(UMT)试纸条在检测恶性疟原虫组氨酸丰富蛋白2(HRP2)方面的性能特征,HRP2是一种多组氨酸抗原,存在于发热患者尿液中,用于疟疾诊断。
这是一项观察性研究,在正常现场环境中使用基于尿液的疟疾检测试剂盒进行疟疾诊断。在尼日利亚东南部传播季节高低不同时期,对埃努古州七家门诊诊所中出现发热(≥37.5°C)的203名个体进行了登记。对连续登记受试者的尿液和血液匹配样本进行UMT检测和血涂片显微镜检查。
以血涂片显微镜检查为标准,疾病患病率为41.2%,UMT的敏感性为83.75%(CI:73.81至91.95%,Kappa 0.665,p = 0.001)。UMT的最低检测限为120个寄生虫/微升,但在寄生虫密度小于或等于200个寄生虫/微升时敏感性为50%,在密度≥201个寄生虫/微升时敏感性为89.71%,特异性为83.48%。阳性和阴性预测值分别为77.91%和88.07%。
与血涂片显微镜检查相比,UMT显示出中等水平的敏感性。该检测试剂盒需要进一步提高其敏感性,以便能够在疟疾流行地区用于现场检测。