Cepeid Xpert Xpress SARS-CoV-2测试的多中心评估。
- 作者列表："Loeffelholz MJ","Alland D","Butler-Wu SM","Pandey U","Perno CF","Nava A","Carroll KC","Mostafa H","Davies E","McEwan A","Rakeman JL","Fowler RC","Pawlotsky JM","Fourati S","Banik S","Banada PP","Swaminathan S","Chakravorty S","Kwiatkowski RW","Chu VC","Kop J","Gaur R","Sin MLY","Nguyen D","Singh S","Zhang N","Persing DH
:Nucleic acid amplification tests (NAATs) are the primary means of identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. We evaluated the analytical and clinical performance characteristics of the Xpert Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2. Analytical sensitivity and specificity/interference were assessed with infectious SARS-CoV-2; other infectious coronavirus species, including SARS-CoV; and 85 nasopharyngeal swab specimens positive for other respiratory viruses, including endemic human coronaviruses (hCoVs). Clinical performance was assessed using 483 remnant upper- and lower-respiratory-tract specimens previously analyzed by standard-of-care (SOC) NAATs. The limit of detection of the Xpert test was 0.01 PFU/ml. Other hCoVs, including Middle East respiratory syndrome coronavirus, were not detected by the Xpert test. SARS-CoV, a closely related species in the subgenus Sarbecovirus, was detected by a broad-range target (E) but was distinguished from SARS-CoV-2 (SARS-CoV-2-specific N2 target). Compared to SOC NAATs, the positive agreement of the Xpert test was 219/220 (99.5%), and the negative agreement was 250/261 (95.8%). A third tie-breaker NAAT resolved all but three of the discordant results in favor the Xpert test. The Xpert test provided sensitive and accurate detection of SARS-CoV-2 in a variety of upper- and lower-respiratory-tract specimens. The high sensitivity and short time to results of approximately 45 min may impact patient management.
: 核酸扩增试验 (NAATs) 是鉴定由新型冠状病毒 (SARS-CoV-2) 引起的急性感染的主要手段。准确和快速的测试结果可以允许更有效地使用保护和隔离资源，并允许快速的治疗干预。我们评估了Xpert Xpress SARS-CoV-2 (Xpert) 测试的分析和临床性能特征，该测试是一种用于SARS-CoV-2的快速自动化分子测试。分析灵敏度和特异度/干扰评估感染性传染性非典型肺炎-CoV-2; 其他感染冠状病毒物种，包括传染性非典型肺炎冠状病毒; 85鼻咽拭子标本阳性其他呼吸道病毒，包括地方性人类冠状病毒es (hCoVs).使用先前通过标准护理 (SOC) NAATs分析的483个残余上、下呼吸道样本评估临床表现。Xpert试验的检测限为0.01 PFU/ml。Xpert试验未检测到其他hcov，包括中东呼吸综合征冠状病毒。传染性非典型肺炎-CoV，近缘种的亚属Sarbecovirus，检测广泛范围的目标 (E)，但不同传染性非典型肺炎-CoV-2 (传染性非典型肺炎-CoV-2-specific N2目标).与SOC NAATs相比，Xpert检验的正一致性为219/220 (99.5%)，负一致性为250/261 (95.8%)。第三个决胜局NAAT解决了除了三个不一致的结果之外的所有结果，支持Xpert测试。Xpert试验提供了灵敏和准确的检测各种上、下呼吸道标本中的SARS-CoV-2。大约45分钟的高灵敏度和短时间的结果可能影响患者管理。
METHODS::The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.
METHODS:OBJECTIVE:To assess the rate of, and risk factors for, human cytomegalovirus viremia (HCMV) in donor+/recipient+ (HCMV serostatus matched) hematopoietic stem-cell transplantation (HSCT) recipients. METHODS:HCMV DNA from 144 donor+/recipient+ HSCT recipients was examined by quantitative polymerase chain reaction (qPCR). RESULTS:The cumulative incidence of HCMV viremia was 69.4% (100/144) during the 48 weeks after HSCT. In a multivariate analysis, acute graft-versus-host disease (aGVHD) was discovered to be a risk factor for the occurrence of HCMV viremia (P = .006). The cumulative incidence of HCMV viremia and increasing DNA loads were significantly associated with aGVHD occurrence (P = .001 for each). The occurrence of late-term HCMV viremia was associated with aGVHD (P = .001) and a higher DNA load during the first 12 weeks after HSCT (P = .04). CONCLUSIONS:aGVHD is a risk factor for HCMV viremia. Recipients with aGVHD who have a high HCMV DNA load should be strictly monitored to prevent HCMV activation.
METHODS:OBJECTIVES:Malaria is one of most common tropical diseases encountered in travellers and migrants. It requires an urgent and reliable diagnosis considering its potential severity. In this study, performance of five diagnostic assays were evaluated in a nonendemic region and compared prospectively to quantitative PCR (qPCR). METHODS:A prospective study was conducted at Toulouse Hospital from August 2017 to January 2018 and included all patients with initial Plasmodium screening. Thin and thick blood smears (TnS, TkS), quantitative buffy coat (QBC), rapid diagnostic tests (RDTs) and commercial loop-mediated isothermal amplification (LAMP) were independently performed on each blood sample and compared to our qPCR reference standard. RESULTS:The study encompassed 331 patients, mainly returning from Africa. qPCR detected 73 Plasmodium-positive samples (including 58 falciparum). Individually, LAMP had a 97.3% (71/73) sensitivity, far ahead of TnS (84.9%, 62/73), TkS (86.3%, 63/73), QBC (86.3%, 63/73) and RDT (86.3%, 63/73). RDT demonstrated a high sensitivity for falciparum (98.3%, 57/58) but missed all ovale, malariae and knowlesi infections. Specificity was excellent for all techniques (99.6-100%). The most sensitive diagnosis strategies were TnS + RDT (95.9%, 70/73), TnS + LAMP (97.3%, 71/73) and TnS + RDT + LAMP (100%, 73/73), about 10% higher than strategies using exclusively microscopy, TkS + TnS (87.7%, 64/73) or QBC + TnS (87.7%, 64/73). TnS remains necessary for Plasmodium species identification and quantification. Adding sequentially TnS only on LAMP-positive samples did not decrease TnS + LAMP strategy sensitivity. CONCLUSIONS:In nonendemic countries, the currently recommended microscopy-based strategies seem unsatisfactory for malaria diagnosis considering RDT and LAMP performance, two rapid and sensitive assays that require limited training.