scholarly journals Strategy for a rapid screening and surveillance of SARS-CoV-2 variants by real time RT-PCR: a key tool that allowed control and delay in Delta spread in Cordoba, Argentina

Author(s):  
Gonzalo Manuel Castro ◽  
Paola Sicilia ◽  
Maria Laura Bolzon ◽  
Laura Lopez ◽  
Maria Gabriela Barbas ◽  
...  

Background: SARS-CoV-2 variants of concern (VOC) and interest (VOI) present mutations in reference to the original virus, being more transmissible. We implemented a rapid strategy for the screening of SARS-CoV-2 VOC/VOIs using real time RT-PCR and performed monitoring and surveillance of the variants in our region. Methods: consecutive real-time RT-PCRs for detection of the relevant mutations/deletions present in the Spike protein in VOC/VOIs (TaqMan SARS-CoV-2 Mutation Panel, Applied Biosystems) were implemented. An algorithm was established and 3941 SARS-CoV-2 RNA samples (Cts<30) obtained from oropharyngeal swabs from infected individuals in Cordoba, Argentina, between January and October 2021, were analyzed. Results: the strategy of choice included a first screening of 3 mutations (N501Y, E484K, L452R) followed by the detection of other mutations/deletions based on the results. The analyses of the samples showed introductions of VOCs Alpha and Gamma in February and March 2021, respectively. Since then, Alpha presented a low to moderate circulation (1.7% of the SARS-CoV-2 currently detected). Gamma showed an exponential increase, with a peak of detection in July (72%), until reaching a current frequency of 41.1%. VOC Delta was first detected in July in travellers and currently represents 35% of detections in the community. VOI Lambda presented a gradual increase, showing a current frequency of 29%. Conclusions: we report a useful tool for VOC/VOI detection, innovative for Argentina, capable to quickly and cost-effectively monitor currently recognized variants. It was key in the early detection of Delta, being able to implement measures to delay its dissemination.

2020 ◽  
pp. 175717742097679
Author(s):  
Kordo Saeed ◽  
Emanuela Pelosi ◽  
Nitin Mahobia ◽  
Nicola White ◽  
Christopher Labdon ◽  
...  

Background: We report an outbreak of SARS coronavirus-2 (SARS-CoV-2) infection among healthcare workers (HCW) in an NHS elective healthcare facility. Methodology: A narrative chronological account of events after declaring an outbreak of SARS-CoV-2 among HCWs. As part of the investigations, HCWs were offered testing during the outbreak. These were: (1) screening by real-time reverse transcriptase polymerase chain reaction (RT- PCR) to detect a current infection; and (2) serum samples to determine seroprevalence. Results: Over 180 HCWs were tested by real-time RT-PCR for SARS-CoV-2 infection. The rate of infection was 15.2% (23.7% for clinical or directly patient-facing HCWs vs. 4.8% in non-clinical non-patient-facing HCWs). Of the infected HCWs, 57% were asymptomatic. Seroprevalence (SARS-CoV-2 IgG) among HCWs was 13%. It was challenging to establish an exact source for the outbreak. The importance of education, training, social distancing and infection prevention practices were emphasised. Additionally, avoidance of unnecessary transfer of patients and minimising cross-site working for staff and early escalation were highlighted. Establishing mass and regular screening for HCWs are also crucial to enabling the best care for patients while maintaining the wellbeing of staff. Conclusion: To our knowledge, this is the first UK outbreak report among HCWs and we hope to have highlighted some key issues and learnings that can be considered by other NHS staff and HCWs globally when dealing with such a task in future.


2005 ◽  
Vol 173 (4S) ◽  
pp. 145-145 ◽  
Author(s):  
Martin Schostak ◽  
Hans Krause ◽  
Jens Köllermann ◽  
Mark Schrader ◽  
Bernd Straub ◽  
...  

2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske

2007 ◽  
Vol 120 (20) ◽  
pp. 1803-1808 ◽  
Author(s):  
Hong-hu ZHU ◽  
Yan-rong LIU ◽  
Ya-zhen QIN ◽  
Bin JIANG ◽  
Fu-xiang SHAN ◽  
...  

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1091
Author(s):  
Ali A. Rabaan ◽  
Raghavendra Tirupathi ◽  
Anupam A Sule ◽  
Jehad Aldali ◽  
Abbas Al Mutair ◽  
...  

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.


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