Viral nucleic acid detection with CRISPR-Cas12a using high contrast cleavage detection on micro-ring resonator biosensors

Author(s):  
Li Liu ◽  
Mike Dubrovsky ◽  
Sarat Gundavarapu ◽  
Diedrik Vermeulen ◽  
Ke Du
2020 ◽  
Author(s):  
Rui Hu

The Corona Virus Disease 2019 (COVID-19) has the characteristics of fast propagation speed and strong pathogenicity and has attracted wide attention of people, medical workers, and researchers around the world. Accurate, rapid, and timely screening and diagnosis of COVID-19 is of great significance to control the development of the epidemic situation and save the lives of patients. Currently, the detection of viral nucleic acid and lung CT is the main screening and diagnostic methods of COVID-19. Nucleic acid detection has the advantages of fast, strong specificity and high sensitivity, but there is a certain false-negative rate. CT result of lung examination is visual, but it is not typical due to the uncertain time of clinical symptoms and the early medical intervention. Therefore, the diagnosis of COVID-19 should include a combination of epidemiological history, clinical symptoms, imaging, and laboratory tests.


Lab on a Chip ◽  
2018 ◽  
Vol 18 (13) ◽  
pp. 1928-1935 ◽  
Author(s):  
Wenhan Liu ◽  
Jagotamoy Das ◽  
Adam H. Mepham ◽  
Carine R. Nemr ◽  
Edward H. Sargent ◽  
...  

Integrated devices for automated nucleic acid testing (NAT) are critical for infectious disease diagnosis to be performed outside of centralized laboratories.


Author(s):  
Chenyao Lin ◽  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Shuang Huang ◽  
...  

AbstractBackgroundIn December 2019, a novel coronavirus (SARS-CoV-2) infected pneumonia (COVID-19) occurred in Wuhan, China. Diagnostic test based on real-time reverse transcription polymerase chain reaction assay (qRT-PCR) was the main means of confirmation, and sample collection was mostly throat swabs, which was easy to miss the diagnosis. It is necessary to seek specimen types with higher detection efficiency and accuracy.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by qRT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using qRT-PCR assay (P=0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens are significantly higher than throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.


2020 ◽  
Author(s):  
Meng Xu ◽  
Xun Liu ◽  
Chuhong Su ◽  
Yuping Zeng ◽  
Jinqian Zhang ◽  
...  

AbstractBackgroundCoronavirus disease 2019 (COVID-19) has become a global health problem. We aim to investigate the changes in the results of viral nucleic acid tests on pharyngeal swabs and feces of patients with COVID-19 and CT imaging of lungs as the disease progresses.MethodsSeven patients with COVID-19 in the third affiliated hospital of Sun Yat-sen University Yuedong Hospital were retrospectively enrolled with clinical features, including imaging staging, and performance characteristics of viral nucleic acid test results of pharyngeal swabs and feces. The dynamic changes of these features were observed during hospitalization, and therapeutic effect and prognosis of patients were evaluated.ResultsThe results of seven cases with COVID-19 were positive for viral nucleic acid tests on pharyngeal swabs early after the onset of symptoms, and then turned negative; while the results of viral nucleic acid tests on feces were persistently positive in the mid-term clinical treatment and recovery period. And the viral nucleic acid test results were capricious in three cases. Pulmonary CT imaging showed characteristic changes in early, advanced and recovery phases.ConclusionThe application of viral nucleic acid detection and pulmonary CT imaging can be used for screening of suspected cases. Fecal nucleic acid test should be recommended as the reference of discharge standard, in order to minimize the risk of transmission from digestive tract.


2021 ◽  
Vol 4 ◽  
pp. 2
Author(s):  
Jaya Kaushik ◽  
Vikas Marwah ◽  
Ankita Singh ◽  
Y. V. K. Chaitanya ◽  
Rajeev Mohan Gupta ◽  
...  

Objectives: The purpose of the study was to detect the presence of viral ribonucleic acid of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in conjunctival swab along with nasopharyngeal swab specimens of Coronavirus disease 2019 (COVID-19) patients. Material and Methods: Thirty COVID-19 patients with at least one sample positive for real-time reverse transcription-polymerase chain reaction for SARS-CoV-2 in nasopharyngeal swab with the presence or absence of ocular manifestations were included in the study. The conjunctival swab along with nasopharyngeal swab of each patient was collected and sent to microbiology lab for evaluation and analysis of viral nucleic acid to assess the viral load. Results: Out of 30 patients, 21 patients (70%) were males and the remaining nine patients (30%) were females. Mean age of the patients in the study was 44.80 ± 15.37 years. One patient had conjunctivitis as ocular manifestation. Two (6.7%) out of 30 patients were positive for RT-PCR SARS-CoV-2 in the conjunctival swab. There was no statistical correlation between nasopharyngeal swab and conjunctival swab positivity using Pearson’s correlation coefficient (r) = 0.010; P = 0.995 (>0.05). Conclusion: The results of the study revealed that SARS-CoV-2 can also be detected in conjunctival swabs of confirmed cases of COVID-19 patients. Although, in comparison to nasopharyngeal and throat swabs the rate of detection of SARS-CoV-2 in conjunctival swabs is relatively less, still diligent care and precautions should be practiced during the ophthalmic evaluation of COVID-19 patients.


2020 ◽  
Vol 58 (7) ◽  
pp. 1089-1094 ◽  
Author(s):  
Chenyao Lin ◽  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Shuang Huang ◽  
...  

AbstractObjectivesIn December 2019, a novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19) occurred in Wuhan, China. Laboratory-based diagnostic tests utilized real-time reverse transcriptase polymerase chain reaction (RT-PCR) on throat samples. This study evaluated the diagnostic value to analyzing throat and sputum samples in order to improve accuracy and detection efficiency.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by the RT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using the RT-PCR assay (p = 0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens were significantly higher than those from throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.


2014 ◽  
Vol 155 (26) ◽  
pp. 1019-1023
Author(s):  
Judit Gervain

The successful therapy of hepatitis C viral infection requires that the illness is diagnosed before the development of structural changes of the liver. Testing is stepwise consisting of screening, diagnosis, and anti-viral therapy follow-up. For these steps there are different biochemical, serological, histological and molecular biological methods available. For screening, alanine aminotransferase and anti-HCV tests are used. The diagnosis of infection is confirmed using real-time polymerase chain reaction of the viral nucleic acid. Before initiation of the therapy liver biopsy is recommended to determine the level of structural changes in the liver. Alternatively, transient elastography or blood biomarkers may be also used for this purpose. Differential diagnosis should exclude the co-existence of other viral infections and chronic hepatitis due to other origin, with special attention to the presence of autoantibodies. The outcome of the antiviral therapy and the length of treatment are mainly determined by the viral genotype. In Hungary, most patients are infected with genotype 1, subtype b. The polymorphism type that occurs in the single nucleotide located next to the interleukin 28B region in chromosome 19 and the viral polymorphism type Q80K for infection with HCV 1a serve as predictive therapeutic markers. The follow-up of therapy is based on the quantitative determination of viral nucleic acid according to national and international protocols and should use the same method and laboratory throughout the treatment of an individual patient. Orv. Hetil., 2014, 155(26), 1019–1023.


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