Diagnostic Tools for Coronavirus Disease (COVID-19): Comparing CT and RT-PCR Viral Nucleic Acid Testing

2020 ◽  
Vol 215 (4) ◽  
pp. 834-838 ◽  
Author(s):  
Joseph V. Waller ◽  
Parveer Kaur ◽  
Amy Tucker ◽  
Keldon K. Lin ◽  
Michael J. Diaz ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Tools ◽  
Nucleic Acid Testing ◽  
Rt Pcr ◽  
Viral Nucleic Acid

scholarly journals Cases Report of Cured Novel Coronavirus-infected Pneumonia Patients with Viral Nucleic Acid Test Positive in Fecal Specimens

2020 ◽  
Author(s):  
Mei Han ◽  
Jingbo Zou ◽  
Wenguang Tian ◽  
Xiaoyu Wei ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Molecular Diagnostic ◽  
Clinical Practices ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Nucleic Acid Test ◽  
Assessment Standard ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Respiratory Specimens

Abstract Background: The outbreak of the novel coronavirus in China (COVID-19) represents a significant and urgent threat to global health. We report here five cases of COVID-19 infection patients in our clinical practices who are medically stable and presumed to successfully “cleared” the virus after antiviral treatments. Case presentation: The clinical evaluation depends on the viral nucleic acid test in respiratory specimens by real-time PCR reverse transcription (RT-PCR) assays according to the authorized guidance. We found that the stool samples of these cured patients remain positive in RT-PCR assay while the virus is undetectable in respiratory specimens. RT-PCR molecular diagnostic assay was designed to specifically detect the presence of viral RNA. Thus, the positive result in the fecal specimens implies the existence of viable virions with the patients. Conclusions: This highlights the importance to look closely at the assessment standard of medical treatment, as well as the need for reevaluation of the criteria for the initial screening, prevention, and care of patients with this emerging infection.

scholarly journals Differential diagnosis for suspected cases of coronavirus disease 2019: a retrospective study

2020 ◽  
Author(s):  
Qiong Chi ◽  
Xinjian Dai ◽  
Xiangao Jiang ◽  
Lefei Zhu ◽  
Junyan Du ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Nucleic Acid ◽  
Influenza B ◽  
Nucleic Acid Testing ◽  
Negative Group ◽  
Rt Pcr ◽  
Positive Group ◽  
Imaging Characteristics ◽  
Imaging Results ◽  
Wbc Count

Abstract Background Since December 2019, the coronavirus disease 2019 (COVID-19) has infected more than 2,310,000 people and killed over hundreds of thousands people worldwide. However, Differential diagnosis remains difficult for suspected cases of COVID-19 and need to be improved to reduce misdiagnosis. Methods Sixty-eight cases of suspected COVID-19 treated in Wenzhou Central Hospital from January 21 to February 20, 2020 were divided into confirmed and COVID-19-negative groups based on the results of real-time reverse transcriptase polymerase chain reaction (RT-PCR) nucleic acid testing of the novel coronavirus in throat swab specimens to compare the clinical symptoms and laboratory and imaging results between the groups. Results Among suspected patients, 17 were confirmed to COVID-19-positive group and 51 were distinguished to COVID-19-negative group. Patients with reduced white blood cell (WBC) count were more common in the COVID-19-positive group than in the COVID-19-negative group (29.4% vs 3.9%, P = 0.003). Subsequently, correlation analysis indicated that there was a significant inverse correlation existed between WBC count and temperature in the COVID-19-positive patients (r=-0.587, p = 0.003), instead of the COVID-19-negative group. But reduced lymphocyte count was no different between the two groups (47.1% vs 25.5%, P = 0.096). More common chest imaging characteristics of the confirmed COVID-19 cases by high-resolution computed tomography (HRCT) included ground-glass opacities (GGOs), multiple patchy shadows, and consolidation with bilateral involvement than COVID-19-negative group (82.4% vs 31.4%, p = 0.0002; 41.2% vs 17.6% vs p = 0.048; 76.5% vs 43.1%, p = 0.017; respectively). Through multiplex RT-PCR nucleic acid testing, 2 case of influenza A, 3 cases of influenza B, 2 cases of adenovirus, 2 cases of Chlamydia pneumonia, and 7 cases of Mycoplasma pneumoniae were diagnosed in the COVID-19-negative group. Conclusions Reduced WBC count inversely correlating with the severity of fever, GGOs, multiple patchy shadows, and consolidation in chest HRCT and clustered infection are features in the confirmed COVID-19 group but not unique. Multiplex RT-PCR nucleic acid testing helped exclude pathogenic diagnosis in COVID-19 patients.

A fully-integrated and automated testing device for PCR-free viral nucleic acid detection in whole blood

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 ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Nucleic Acid ◽  
Disease Diagnosis ◽  
Automated Testing ◽  
Nucleic Acid Detection ◽  
Nucleic Acid Testing ◽  
Testing Device ◽  
Viral Nucleic Acid ◽  
Fully Integrated ◽  
Integrated Devices

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

Effect of viral nucleic acid testing on contamination frequency of manufacturing plasma pools

Transfusion ◽  
2008 ◽  
Vol 48 (5) ◽  
pp. 822-826 ◽  
Author(s):  
C. Micha Nübling ◽  
Uwe Unkelbach ◽  
Michael Chudy ◽  
Rainer Seitz
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Testing ◽  
Viral Nucleic Acid

scholarly journals Nucleic Acid Testing of SARS-CoV-2

2021 ◽  
Vol 22 (11) ◽  
pp. 6150
Author(s):  
Hee-Min Yoo ◽  
Il-Hwan Kim ◽  
Seil Kim
Keyword(s):  
Polymerase Chain Reaction ◽  
Nucleic Acid ◽  
Reverse Transcription ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Molecular Diagnostic ◽  
Nucleic Acid Testing ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

The coronavirus disease 2019 (COVID-19) has caused a large global outbreak. It is accordingly important to develop accurate and rapid diagnostic methods. The polymerase chain reaction (PCR)-based method including reverse transcription-polymerase chain reaction (RT-PCR) is the most widely used assay for the detection of SARS-CoV-2 RNA. Along with the RT-PCR method, digital PCR has emerged as a powerful tool to quantify nucleic acid of the virus with high accuracy and sensitivity. Non-PCR based techniques such as reverse transcription loop-mediated isothermal amplification (RT-LAMP) and reverse transcription recombinase polymerase amplification (RT-RPA) are considered to be rapid and simple nucleic acid detection methods and were reviewed in this paper. Non-conventional molecular diagnostic methods including next-generation sequencing (NGS), CRISPR-based assays and nanotechnology are improving the accuracy and sensitivity of COVID-19 diagnosis. In this review, we also focus on standardization of SARS-CoV-2 nucleic acid testing and the activity of the National Metrology Institutes (NMIs) and highlight resources such as reference materials (RM) that provide the values of specified properties. Finally, we summarize the useful resources for convenient COVID-19 molecular diagnostics.

scholarly journals Continued nucleic acid tests for SARS-CoV-2 following discharge of patients with COVID-19 in Lu’an, China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11617
Author(s):  
Yong Lyu ◽  
Danni Wang ◽  
Xiude Li ◽  
Tianqi Gong ◽  
Pengpeng Xu ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Throat Swab ◽  
Nucleic Acid Testing ◽  
Rt Pcr ◽  
Positive Group ◽  
The Third ◽  
Anal Swab ◽  
Discharge Criteria ◽  
Pcr Test

Background Studies have shown that discharged Coronavirus disease 2019 (COVID-19) patients have retested positive for SARS-CoV-2 during a follow-up RT-PCR test. We sought to assess the results of continued nucleic acid testing for SARS-CoV-2 patients in COVID-19 patients after they were discharged in Lu’an, China. Methods We conducted RT-PCR tests on sputum, throat swabs, fecal or anal swabs, and urine samples collected from 67 COVID-19 patients following discharge. Samples were collected on the 7th and 14th days following discharge. Patients testing positive on the 7th or 14th day were retested after 24 hours until they tested negative twice. Results Seventeen (17/67, 25.4%) discharged COVID-19 patients had a positive RT-PCR retest for SARS-CoV-2. Among them, 14 (82.4%) were sputum positive, five (29.4%) were throat swab positive, seven (41.2%) were fecal or anal swab positive, one (5.9%) was urine sample positive, five (29.4%) were both sputum and throat swab positive, four (23.5%) were both sputum and fecal test positive, and one (5.9%) was positive of all four specimens. The shortest period of time between discharge and the last positive test was 7 days, the longest was 48 days, and the median was 16 days. The proportion of positive fecal or anal swab tests increased from the third week. The median Cq cut-off values after onset were 26.7 after the first week, 37.7 the second to sixth week, and 40 after the sixth week. There were no significant differences between the RT-PCR retest positive group and the unrecovered positive group. Conclusions There was a high proportion of patients who retested positive for COVID-19. Discharge criteria have remained fairly consistent so we encourage regions affected by COVID-19 to appropriately amend their current criteria.

Culicoides Oxystoma a Potential Vector for Transmission of Bluetongue Virus 16 in Southern India

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Minakshi Prasad ◽  
Koushlesh Ranjan ◽  
Basanti Brar ◽  
Gaya Prasad
Keyword(s):  
Cell Culture ◽  
Nucleic Acid ◽  
Bluetongue Virus ◽  
Cytopathic Effect ◽  
Migration Pattern ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Vp2 Gene ◽  
Potential Vector ◽  
Culicoides Oxystoma

Bluetongue (BT) is a Culicoides vector borne disease of domestic and wild ruminants. It is caused by bluetongue virus (BTV). BT is infectious but non-contagious disease. The head–thorax region of Culicoides Oxystoma vector trapped on animal farm in TN was triturated and inoculated in BHK- 21 cell culture. After few blind passages it showed cytopathic effect (CPE) in cell culture. After appearance of 75% cytopathic effect in BHK 21 cell culture, viral nucleic acid was extracted. The RNA-PAGE analysis showed BTV specific characteristics migration pattern of 3:3:3:1. Viral nucleic acid was allowed for cDNA synthesis followed by NS1 and VP2 gene based RT-PCR. The NS1 gene RT-PCR, CPE and specific migration pattern in RNA-PAGE confirmed the sample as BTV. The VP2 gene based serotype specific RT-PCR identified the isolate as BTV serotype 16. The study suggested that Culicoides oxystoma could be a potential vector for transmission of BTV in southern India.

scholarly journals Potential False-Negative Nucleic Acid Testing Results for Severe Acute Respiratory Syndrome Coronavirus 2 from Thermal Inactivation of Samples with Low Viral Loads

2020 ◽  
Vol 66 (6) ◽  
pp. 794-801 ◽  
Author(s):  
Yang Pan ◽  
Luyao Long ◽  
Daitao Zhang ◽  
Tingting Yuan ◽  
Shujuan Cui ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Severe Acute Respiratory Syndrome ◽  
Thermal Inactivation ◽  
Rna Virus ◽  
False Negative ◽  
Heat Inactivation ◽  
Nucleic Acid Testing ◽  
Rt Pcr ◽  
False Negatives ◽  
Viral Loads

Abstract Background Coronavirus disease-2019 (COVID-19) has spread widely throughout the world since the end of 2019. Nucleic acid testing (NAT) has played an important role in patient diagnosis and management of COVID-19. In some circumstances, thermal inactivation at 56°C has been recommended to inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before NAT. However, this procedure could theoretically disrupt nucleic acid integrity of this single-stranded RNA virus and cause false negatives in real-time polymerase chain reaction (RT-PCR) tests. Methods We investigated whether thermal inactivation could affect the results of viral NAT. We examined the effects of thermal inactivation on the quantitative RT-PCR results of SARS-CoV-2, particularly with regard to the rates of false-negative results for specimens carrying low viral loads. We additionally investigated the effects of different specimen types, sample preservation times, and a chemical inactivation approach on NAT. Results Our study showed increased Ct values in specimens from diagnosed COVID-19 patients in RT-PCR tests after thermal incubation. Moreover, about half of the weak-positive samples (7 of 15 samples, 46.7%) were RT-PCR negative after heat inactivation in at least one parallel testing. The use of guanidinium-based lysis for preservation of these specimens had a smaller impact on RT-PCR results with fewer false negatives (2 of 15 samples, 13.3%) and significantly less increase in Ct values than heat inactivation. Conclusion Thermal inactivation adversely affected the efficiency of RT-PCR for SARS-CoV-2 detection. Given the limited applicability associated with chemical inactivators, other approaches to ensure the overall protection of laboratory personnel need consideration.

scholarly journals Nasopharyngeal SARS-CoV-2 viral loads in young children do not differ significantly from those in older children and adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sharline Madera ◽  
Emily Crawford ◽  
Charles Langelier ◽  
Nam K. Tran ◽  
Ed Thornborrow ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Young Children ◽  
Reverse Transcription ◽  
Older Children ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Viral Nucleic Acid ◽  
Viral Loads ◽  
The Us

AbstractThe role of children in the spread of the SARS-CoV-2 coronavirus has become a matter of urgent debate as societies in the US and abroad consider how to safely reopen schools. Small studies have suggested higher viral loads in young children. Here we present a multicenter investigation on over five thousand SARS-CoV-2 cases confirmed by real-time reverse transcription (RT) PCR assay. Notably, we found no discernable difference in amount of viral nucleic acid among young children and adults.

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