LitCovid-sentences  

PMC:7170415 / 13840-17305 JSONTXT 10 Projects

Annnotations TAB TSV DIC JSON TextAE

Id Subject Object Predicate Lexical cue
T103 0-34 Sentence denotes Laboratory-Based Molecular Testing
T104 35-269 Sentence denotes The current diagnostic strategy recommended by the CDC to identify patients with COVID-19 is to test samples taken from the respiratory tract to assess for the presence of 1 or several nucleic acid targets specific to SARS–CoV-2 (25).
T105 270-444 Sentence denotes A nasopharyngeal specimen is the preferred choice for swab-based SARS–CoV-2 testing, but oropharyngeal, mid-turbinate, or anterior nares samples also are acceptable (31, 32).
T106 445-570 Sentence denotes Samples should be obtained by using a flocked swab, if available, to enhance the collection and release of cellular material.
T107 571-625 Sentence denotes Swabs with an aluminum or plastic shaft are preferred.
T108 626-759 Sentence denotes Swabs that contain calcium alginate, wood, or cotton should be avoided, because they may contain substances that inhibit PCR testing.
T109 760-896 Sentence denotes Ideally, swabs should be transferred into universal transport medium immediately after sample collection to preserve viral nucleic acid.
T110 897-1125 Sentence denotes Samples taken from sputum, endotracheal aspirates, and bronchoalveolar lavage also may be sent directly to the microbiology laboratory for processing, and may have greater sensitivity than upper respiratory tract specimens (33).
T111 1126-1191 Sentence denotes Inadequate sample collection may result in a false-negative test.
T112 1192-1302 Sentence denotes After specimen collection, samples undergo RNA extraction followed by qualitative RT-PCR for target detection.
T113 1303-1385 Sentence denotes In the United States, the CDC has developed the most widely used SARS–CoV-2 assay.
T114 1386-1558 Sentence denotes The kit contains PCR primer–probe sets for 2 regions of the viral nucleocapsid gene (N1 and N2), and for the human RNase P gene to ensure the RNA extraction was successful.
T115 1559-1724 Sentence denotes This assay differs from the World Health Organization primer–probe sets, which target the SARS–CoV-2 RNA-dependent RNA polymerase (RdRP) and envelope (E) genes (25).
T116 1725-1958 Sentence denotes Both assays have high analytic sensitivity and specificity for SARS–CoV-2, with minimal cross-reactivity with other circulating strains of coronaviruses, and both use a cycle threshold of less than 40 as the criterion for positivity.
T117 1959-2242 Sentence denotes The CDC kit may be used by state public health laboratories, other laboratories determined by the state to be qualified, and clinical laboratories that meet the regulatory requirements of the Clinical Laboratories Improvement Amendment (CLIA) to perform high-complexity testing (27).
T118 2243-2377 Sentence denotes Dozens of laboratories have applied for Emergency Use Authorization (EUA) from the FDA for their own laboratory-developed assays (34).
T119 2378-2532 Sentence denotes The FDA also has granted an EUA for several commercial assays (35), further expanding the ability of clinical laboratories to use these platforms (Table).
T120 2533-2539 Sentence denotes Table.
T121 2540-2940 Sentence denotes The 28 Commercial SARS–CoV-2 in Vitro Diagnostic Assays Given an EUA From the FDA as of 4 April 2020 The lack of an established reference standard, use of differing sample collection and preparation methods, and an incomplete understanding of viral dynamics across the time course of infection hamper rigorous assessment of the diagnostic accuracy of the many newly introduced SARS–CoV-2 assays (36).
T122 2941-3054 Sentence denotes Serum and urine are usually negative for the presence of viral nucleic acid, regardless of illness severity (33).
T123 3055-3216 Sentence denotes Of importance, the ability of RT-PCR assays to rule out COVID-19 on the basis of upper respiratory tract samples obtained at a single time point remains unclear.
T124 3217-3465 Sentence denotes Conversely, after a patient has had a positive test result, several authorities have recommended obtaining at least 2 negative upper respiratory tract samples, collected at intervals of 24 hours or longer, to document SARS–CoV-2 clearance (37, 38).