Stauffer William M, Cartwright Charles P, Olson Douglas A, Juni Billie Anne, Taylor Charlotte M, Bowers Susan H, Hanson Kevan L, Rosenblatt Jon E, Boulware David R
Department of Medicine, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Clin Infect Dis. 2009 Sep 15;49(6):908-13. doi: 10.1086/605436.
Approximately 4 million US travelers to developing countries are ill enough to seek health care, with 1500 malaria cases reported in the United States annually. The diagnosis of malaria is frequently delayed because of the time required to prepare malaria blood films and lack of technical expertise. An easy, reliable rapid diagnostic test (RDT) with high sensitivity and negative predictive value (NPV), particularly for Plasmodium falciparum, would be clinically useful. The objective of this study was to determine the diagnostic performance of a RDT approved by the US Food and Drug Administration compared with traditional thick and thin blood smears for malaria diagnosis.
This prospective study tested 852 consecutive blood samples that underwent thick and thin smears and blinded malaria RDTs at 3 hospital laboratories during 2003-2006. Polymerase chain reaction verified positive test results and discordant results.
Malaria was noted in 95 (11%) of the 852 samples. The RDT had superior performance than the standard Giemsa thick blood smear (p = .003). The RDT's sensitivity for all malaria was 97% (92 of 95 samples), compared with 85% (81 of 95) for the blood smear, and the RDT had a superior NPV of 99.6%, compared with 98.2% for the blood smear (p = .001). The P. falciparum performance was excellent, with 100% rapid test sensitivity, compared with only 88% (65 of 74) by blood smear (p = .003).
This operational study demonstrates that the US Food and Drug Administration-approved RDT for malaria is superior to a single set of blood smears performed under routine US clinical laboratory conditions. The most valuable clinical role of the RDT is in the rapid diagnosis or the exclusion of P. falciparum malaria, which is particularly useful in outpatient settings when evaluating febrile travelers.
每年约有400万前往发展中国家的美国旅行者患病严重到需要寻求医疗护理，美国每年报告1500例疟疾病例。由于制备疟原虫血涂片所需时间以及缺乏专业技术知识，疟疾的诊断常常被延迟。一种简便、可靠且具有高灵敏度和阴性预测值（NPV）的快速诊断检测（RDT），尤其是针对恶性疟原虫的检测，在临床上会很有用。本研究的目的是确定一种经美国食品药品监督管理局批准的RDT与传统厚血涂片和薄血涂片在疟疾诊断方面的诊断性能。
这项前瞻性研究在2003 - 2006年期间对3家医院实验室的852份连续血样进行了检测，这些血样同时进行了厚涂片和薄涂片以及盲法疟疾RDT检测。聚合酶链反应验证了阳性检测结果和不一致的结果。
在852份样本中有95份（11%）检测出疟疾。RDT的性能优于标准吉姆萨厚血涂片（p = 0.003）。RDT对所有疟疾的灵敏度为97%（95份样本中的92份），而血涂片为85%（95份中的81份），并且RDT的NPV更高，为99.6%，血涂片为98.2%（p = 0.001）。恶性疟原虫的检测性能出色，快速检测灵敏度为100%，而血涂片仅为88%（74份中的65份）（p = 0.003）。
这项实用性研究表明，经美国食品药品监督管理局批准的疟疾RDT优于在美国常规临床实验室条件下进行的单次血涂片检测。RDT最有价值的临床作用在于快速诊断或排除恶性疟原虫疟疾，这在评估发热旅行者的门诊环境中特别有用。
