scholarly journals Comparing lateral flow testing with a rapid RT-PCR method for SARS-CoV-2 detection in the UK

2021 ◽  
Author(s):  
Andrew Taylor ◽  
Ronan Calvez ◽  
Mark Atkins ◽  
Colin G Fink
Keyword(s):  
Scientific Evidence ◽  
Lateral Flow ◽  
Careful Examination ◽  
Rt Pcr ◽  
Laboratory Staff ◽  
Viral Loads ◽  
Pcr Method ◽  
Uk Government ◽  
Us Fda ◽  
The Uk

AbstractIn late 2019, SARS-CoV-2 emerged in the Wuhan province of China. Rapid global spread led to the Covid-19 pandemic. Rapid and accurate detection of SARS-CoV-2 has become a vitally important tool in controlling the spread of the virus. Lateral flow devices (LFDs) offer the potential advantage of speed and on-site testing. The sensitivity of these devices compared to the gold standard RT-PCR has been questioned. We compared the performance of the Innova lateral flow kit, recommended by the UK government, with our rapid in-house RT-PCR protocol using stored positive patient samples. The LFD device was found to be 6,000-10,000 times less sensitive than RT-PCR for the detection of SARS-CoV-2. Overall, the LFD detected 46.2% of the positives detected by RT-PCR. 50% of the LFD results were observed to be weak positives, only visible after careful examination by experienced laboratory staff. At lower viral loads, such as 10,000-100,000 RNA copies/ml, the LFD detected 22.2% of positives. In addition, two strong positives (3 and 1.5 million RNA copies/ml) were not detected by the LFD. The argument for use of LFD kits, despite their lack of sensitivity, is that they detect infectious virus and hence contagious individuals. At present, there is a lack of scientific evidence supporting this claim. The LFD used in the UK fails to identify individuals with considerable viral loads and has been subject to a class I recall by the US FDA but is still approved and recommended for use by the UK government. We believe that using LFD testing for assessing SARS-CoV-2 infection risk is a strategy which has risks that outweigh any benefits.

scholarly journals Insufficient Sensitivity of RNA Dependent RNA Polymerase Gene of SARS-CoV-2 Viral Genome as Confirmatory Test using Korean COVID-19 Cases

2020 ◽  
Author(s):  
Soyoun Kim ◽  
Dong-Min Kim ◽  
Baeckseung Lee
Keyword(s):  
Diagnostic Methods ◽  
Confirmatory Test ◽  
Test Results ◽  
Rt Pcr ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Pcr Method ◽  
Who Guideline ◽  
Rna Polymerase Gene ◽  
Insufficient Sensitivity

Since mid-December of 2019, coronavirus disease 2019 (COVID-19) has been spreading from Wuhan, China. As of February 21, total 75,773 confirmed cases worldwide have spread to more than two dozen countries. Transmission of COVID-19 can occur early in the course of infection since SARS-CoV-2 viral loads in asymptomatic patients are similar to that in the symptomatic patients. Therefore, more sensitive diagnostic methods are needed to detect early phase of the infection to prevent secondary or tertiary spreads. Here, we compare the RT-PCR confirmatory test results using two different SARS-CoV-2 viral RNAs from two Korean COVID-19 confirmed cases.RT-PCR method targeting the RdRP gene, which was recommended by WHO guideline, was less sensitive than targeting N genes (as per CDC guideline). Because many countries follow the WHO guideline, our findings may contribute to the early diagnosis of COVID-19.

scholarly journals Diagnostic accuracy and utility of SARS-CoV-2 antigen lateral flow assays in medical admissions with possible COVID-19

2021 ◽  
Author(s):  
Hamish Houston ◽  
Ankur Gupta-Wright ◽  
Edward Toke-Bjolgerud ◽  
James Biggin-Lamming ◽  
Laurence John
Keyword(s):  
Diagnostic Accuracy ◽  
Hospital Admissions ◽  
Case Definition ◽  
Acute Hospital ◽  
Lateral Flow ◽  
Rt Pcr ◽  
Lateral Flow Assays ◽  
Qualitative Test ◽  
The Uk

AbstractWe evaluated diagnostic accuracy of the Innova SARS-CoV-2 Antigen Rapid Qualitative Test compared to SARS-CoV-2 RT-PCR from nasopharyngeal swabs in adult admissions who met the COVID-19 case definition at a busy acute hospital in the UK. We found the Innova SARS-CoV-2 Antigen Rapid Qualitative Test had a good specificity in patients with symptoms of COVID-19 presenting to hospital. The Innova LFA can be used to rapidly identify COVID-19 cases amongst hospital admissions meeting the COVID-19 case definition, allowing patients to be allocated to COVID-19 cohort areas.

The UK Government agrees to create the world's largest marine reserve around the Pitcairn Islands, a UK Overseas Territory in the South Pacific

2015 ◽  
Vol 21 (2) ◽  
pp. 108 ◽  
Author(s):  
Terence P. Dawson
Keyword(s):  
Scientific Evidence ◽  
Marine Reserve ◽  
Evidence Base ◽  
Concerted Effort ◽  
Members Of Parliament ◽  
The Pacific ◽  
Advocacy Campaigns ◽  
The Pacific Ocean ◽  
Uk Government ◽  
The Uk

In March 2015, the UK Government announced their intention to create the World’s largest marine reserve in the territorial waters of the Pitcairn Islands in the Pacific Ocean. This achievement followed a concerted effort by a consortium of scientists, environmental campaigners and Members of Parliament, who engaged cooperatively in the building of the scientific evidence base and advocacy campaigns.

Detection of SARs CoV-2 during initial phase of pandemic from population of banas kantha district of Gujarat-India with special emphasis on pooled samples

2021 ◽  
Vol 7 (4) ◽  
pp. 295-299
Author(s):  
Hiren Patel ◽  
Parijat N Goswami
Keyword(s):  
Viral Load ◽  
Age Groups ◽  
High Viral Load ◽  
Rt Pcr ◽  
Viral Loads ◽  
Corona Virus ◽  
Asymptomatic Patients ◽  
Care Workers ◽  
Pcr Method ◽  
Pharynx Swab

Corona virus (SARs CoV-2) has caused immense effect on morbidity and mortality of the population globally. We undertook this study as we are a part of one of the network laboratories of ICMR to test the patient’s sample by RT PCR for the ORF 1 ab gene of corona virus. : For a period of one and half months (14 April to 31 May 2020) we tested the nasopharynx and oro-pharynx swab samples sent to us in VTM from the assigned districts of Gujarat. All the samples were subjected to RT PCR method by following standard methods. Total of 9.04%(256/2833) population was positive and 4.73%(139/2833) belonged to age groups 21-40 and 2.33% (66/2833) to 41-60yrs. Above the age of 60yrs there were only 0.95% (22/2833) cases which were positive. It was advantageous to pool the samples. Out of the number of pools prepared, we reported around 80% negative and rest were positive in pools. The study also included association of viral load and infectivity. We found that 12% of the asymptomatic people and 5.1% of symptomatic individuals had high viral load. : It is seen that the incidence of Novel corona virus -19 detection by RT PCR is a reliable method and the establishment of the Ct value and infectivity of the patient to the health care workers and relatives needs to be taken care of. Also, the study presents asymptomatic patients having high viral loads being highly infective.

scholarly journals Analytical Performance of Quantitative DiaSorin Liaison SARS-COV-2 Antigen Test for the Asymptomatic Population

2022 ◽  
Vol 9 ◽  
Author(s):  
Gema Fernández-Rivas ◽  
Jaume Barallat ◽  
Victoria Gonzalez ◽  
Silvia Martinez ◽  
Antoni E. Bordoy ◽  
...  
Keyword(s):  
High Specificity ◽  
Risk Groups ◽  
Lateral Flow ◽  
Analytical Performance ◽  
Rt Pcr ◽  
Infectious Dose ◽  
Viral Loads ◽  
Nasal Swabs ◽  
Tissue Culture Infectious Dose ◽  
Flow Techniques

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antigen (Ag) tests have been widely employed to identify patients for a rapid diagnosis and pandemic control. Rapid lateral-flow techniques are currently the most used, but automated technologies have emerged as another viable alternative to molecular methods. We aimed to evaluate the analytical performance of the DiaSorin Liaison SARS-CoV-2 Ag test in asymptomatic population and close contacts, for its use as a tool in pandemic control efforts.Material and Methods: A retrospective study was conducted. A total of 861 samples were included, 291 (34%) were positive for SARS-CoV-2 with cycle threshold (Ct) <40, and 570 (66%) were negative.Results: A strong correlation was observed between reverse transcriptase-PCR (RT-PCR) Ct and Ag 50% Tissue Culture Infectious Dose per milliliter (TCID50/ml; r = 0.6486; p < 0.0001) and all RT-PCR negative samples tested negative for the 200 TCID50/ml SARS-Cov-2 Ag cutoff, i.e., a specificity of 100% was reached (95% CI: 99.4–100.0%). Samples with <25 Ct and/or >106 extrapolated copies/ml were reached a sensitivity of 100% (95% IC 97.0–100.0%). For intermediate viral loads (>105 extrapolated copies/ml or <30 Ct), the sensitivity value still exceeded 80%. As with other Ag methods, samples between 30 and 40 Ct could not be detected with a reliable sensitivity.Conclusions: The LIAISON® SARS-CoV-2 Ag assay displays an acceptable sensitivity and a very high specificity that is useful for detecting the presence of SARS-CoV-2 in nasal swabs (NPS) of asymptomatic population or to regular monitoring of risk groups in controlled settings. Additionally, the flexibility in processing different samples and in the sampling preparation process makes this test an option for its use in high throughput laboratories. Automated tests may facilitate result reporting and yield consistent data, while avoiding some of the pitfalls of rapid lateral-flow techniques, such as observer variability.

Monitoring the marine environment for small round structured viruses (SRSVS): a new approach to combating the transmission of these viruses by molluscan shellfish

1998 ◽  
Vol 38 (12) ◽  
pp. 51-56 ◽  
Author(s):  
K. Henshilwood ◽  
J. Green ◽  
D. N. Lees
Keyword(s):  
Enteric Virus ◽  
Winter Period ◽  
Rt Pcr ◽  
Cloning And Sequencing ◽  
New Approach ◽  
Human Enteric Virus ◽  
Different Strains ◽  
The Uk ◽  
Public Health Protection

This study investigates human enteric virus contamination of a shellfish harvesting area. Samples were analysed over a 14-month period for Small Round Structured Viruses (SRSVs) using a previously developed nested RT-PCR. A clear seasonal difference was observed with the largest numbers of positive samples obtained during the winter period (October to March). This data concurs with the known winter association of gastroenteric illness due to oyster consumption in the UK and also with the majority of the outbreaks associated with shellfish harvested from this area during the study period. RT-PCR positive amplicons were further characterised by cloning and sequencing. Sequence analysis of the positive samples identified eleven SRSV strains, of both Genogroup I and Genogroup II, occurring throughout the study period. Many shellfish samples contained a mixture of strains with a few samples containing up to three different strains with both Genogroups represented. The observed common occurrence of strain mixtures may have implications for the role of shellfish as a vector for dissemination of SRSV strains. These results show that nested RT-PCR can identify SRSV contamination in shellfish harvesting areas. Virus monitoring of shellfish harvesting areas by specialist laboratories using RT-PCR is a possible approach to combating the transmission of SRSVs by molluscan shellfish and could potentially offer significantly enhanced levels of public health protection.

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