scholarly journals Head-to-head evaluation of seven different seroassays including direct viral neutralisation in a representative cohort for SARS-CoV-2

2021 ◽  
Vol 102 (10) ◽  
Author(s):  
Laura Olbrich ◽  
Noemi Castelletti ◽  
Yannik Schälte ◽  
Mercè Garí ◽  
Peter Pütz ◽  
...  

A number of seroassays are available for SARS-CoV-2 testing; yet, head-to-head evaluations of different testing principles are limited, especially using raw values rather than categorical data. In addition, identifying correlates of protection is of utmost importance, and comparisons of available testing systems with functional assays, such as direct viral neutralisation, are needed.We analysed 6658 samples consisting of true-positives (n=193), true-negatives (n=1091), and specimens of unknown status (n=5374). For primary testing, we used Euroimmun-Anti-SARS-CoV-2-ELISA-IgA/IgG and Roche-Elecsys-Anti-SARS-CoV-2. Subsequently virus-neutralisation, GeneScriptcPass, VIRAMED-SARS-CoV-2-ViraChip, and Mikrogen-recomLine-SARS-CoV-2-IgG were applied for confirmatory testing. Statistical modelling generated optimised assay cut-off thresholds. Sensitivity of Euroimmun-anti-S1-IgA was 64.8%, specificity 93.3% (manufacturer’s cut-off); for Euroimmun-anti-S1-IgG, sensitivity was 77.2/79.8% (manufacturer’s/optimised cut-offs), specificity 98.0/97.8%; Roche-anti-N sensitivity was 85.5/88.6%, specificity 99.8/99.7%. In true-positives, mean and median Euroimmun-anti-S1-IgA and -IgG titres decreased 30/90 days after RT-PCR-positivity, Roche-anti-N titres decreased significantly later. Virus-neutralisation was 80.6% sensitive, 100.0% specific (≥1:5 dilution). Neutralisation surrogate tests (GeneScriptcPass, Mikrogen-recomLine-RBD) were >94.9% sensitive and >98.1% specific. Optimised cut-offs improved test performances of several tests. Confirmatory testing with virus-neutralisation might be complemented with GeneScriptcPassTM or recomLine-RBD for certain applications. Head-to-head comparisons given here aim to contribute to the refinement of testing strategies for individual and public health use.

2021 ◽  
Author(s):  
Laura Olbrich ◽  
Noemi Castelletti ◽  
Yannik Schälte ◽  
Mercè Garí ◽  
Peter Pütz ◽  
...  

AbstractBackgroundSerosurveys are essential to understand SARS-CoV-2 exposure and enable population-level surveillance, but currently available tests need further in-depth evaluation. We aimed to identify testing-strategies by comparing seven seroassays in a population-based cohort.MethodsWe analysed 6,658 samples consisting of true-positives (n=193), true-negatives (n=1,091), and specimens of unknown status (n=5,374). For primary testing, we used Euroimmun-Anti-SARS-CoV-2-ELISA-IgA/IgG and Roche-Elecsys-Anti-SARS-CoV-2; and virus-neutralisation, GeneScript®cPass™, VIRAMED-SARS-CoV-2-ViraChip®, and Mikrogen-recomLine-SARS-CoV-2-IgG, including common-cold CoVs, for confirmatory testing. Statistical modelling generated optimised assay cut-off-thresholds.FindingsSensitivity of Euroimmun-anti-S1-IgA was 64.8%, specificity 93.3%; for Euroimmun-anti-S1-IgG, sensitivity was 77.2/79.8% (manufacturer’s/optimised cut-offs), specificity 98.0/97.8%; Roche-anti-N sensitivity was 85.5/88.6%, specificity 99.8/99.7%. In true-positives, mean and median titres remained stable for at least 90-120 days after RT-PCR-positivity. Of true-positives with positive RT-PCR (<30 days), 6.7% did not mount detectable seroresponses. Virus-neutralisation was 73.8% sensitive, 100.0% specific (1:10 dilution). Neutralisation surrogate tests (GeneScript®cPass™, Mikrogen-recomLine-RBD) were >94.9% sensitive, >98.1% specific. Seasonality had limited effects; cross-reactivity with common-cold CoVs 229E and NL63 in SARS-CoV-2 true-positives was significant.ConclusionOptimised cut-offs improved test performances of several tests. Non-reactive serology in true-positives was uncommon. For epidemiological purposes, confirmatory testing with virus-neutralisation may be replaced with GeneScript®cPass™ or recomLine-RBD. Head-to-head comparisons given here aim to contribute to the refinement of testing-strategies for individual and public health use.


Author(s):  
Patrick D Dissmann ◽  
Felix Koehring ◽  
Florian Fischer

Abstract Until now, systematic surveillance for infectious diseases in refugees is still missing. For that reason, this study aims at illustrating the prevalence of tuberculosis (TB) and notifiable skin diseases in a representative cohort of refugees in Lippe, a district of the federal state of North Rhine-Westphalia, Germany. We collected data on notifiable communicable diseases (TB, scabies, and head lice) from refugees (n = 8946) based on a medical screening after their arrival from October 2014 until May 2016. Data were analysed using descriptive and bivariate methods. Overall, we found 63 of 8764 screened refugees to have an abnormal TB screening result (0.72%). Of 8946 screened refugees, only 51 individuals were found to have scabies (0.57%) and a further 49 were tested positive for head lice (0.55%). The absolute number of TB cases indicate only a moderate public health burden. However, communicable skin diseases can become a problem in crowded holding camps, where they can cause local outbreaks.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gerardo Chowell ◽  
Sushma Dahal ◽  
Raquel Bono ◽  
Kenji Mizumoto

AbstractTo ensure the safe operation of schools, workplaces, nursing homes, and other businesses during COVID-19 pandemic there is an urgent need to develop cost-effective public health strategies. Here we focus on the cruise industry which was hit early by the COVID-19 pandemic, with more than 40 cruise ships reporting COVID-19 infections. We apply mathematical modeling to assess the impact of testing strategies together with social distancing protocols on the spread of the novel coronavirus during ocean cruises using an individual-level stochastic model of the transmission dynamics of COVID-19. We model the contact network, the potential importation of cases arising during shore excursions, the temporal course of infectivity at the individual level, the effects of social distancing strategies, different testing scenarios characterized by the test’s sensitivity profile, and testing frequency. Our findings indicate that PCR testing at embarkation and daily testing of all individuals aboard, together with increased social distancing and other public health measures, should allow for rapid detection and isolation of COVID-19 infections and dramatically reducing the probability of onboard COVID-19 community spread. In contrast, relying only on PCR testing at embarkation would not be sufficient to avert outbreaks, even when implementing substantial levels of social distancing measures.


Author(s):  
Mohammad Jahidur Rahman Khan ◽  
◽  
Selim Reza ◽  
Farzana Mim ◽  
Md Abdullah Rumman ◽  
...  

Rapid and accurate laboratory diagnosis of SARS-CoV-2 infection is crucial for the management of COVID-19 patients and control of the spread of the virus. At the start of the COVID-19 pandemic, Bangladesh had only one government molecular laboratory where real-time RT-PCR will be performed to diagnose SARS-CoV-2 infection. With the increasing number of suspected cases requiring confirmation diagnostic testing, there was a requirement to quickly expand capacity for large-scale testing. The government of Bangladesh established over 100 molecular laboratories within one year to test COVID-19. To fulfil the requirement for expanded testing, the government was compelled to recruit laboratory employees with inadequate experience, technical knowledge, and skills in molecular assays, particularly in processing specimens, interpreting results, recognizing errors, and troubleshooting. As a result, the risk of diagnostic errors, such as cross-contamination, is increased, as is that the risk of false-positive results, which might risk the patient’s health and undermine the efficacy of public health policies, public health response, surveillance programs, and restrictive measures aimed toward containing the outbreak. This review article aims to explain different sources of crosscontamination in the COVID-19 RT-PCR laboratories and the way to forestall them in efficient and practical ways.


2021 ◽  
Vol 26 (28) ◽  
Author(s):  
Samuel Alizon ◽  
Stéphanie Haim-Boukobza ◽  
Vincent Foulongne ◽  
Laura Verdurme ◽  
Sabine Trombert-Paolantoni ◽  
...  

We analysed 9,030 variant-specific RT-PCR tests performed on SARS-CoV-2-positive samples collected in France between 31 May and 21 June 2021. This analysis revealed rapid growth of the Delta variant in three of the 13 metropolitan French regions and estimated a +79% (95% confidence interval: 52–110%) transmission advantage compared with the Alpha variant. The next weeks will prove decisive and the magnitude of the estimated transmission advantages of the Delta variant could represent a major challenge for public health authorities.


Author(s):  
Kelvin Kai-Wang To ◽  
Xin Li ◽  
David Christopher Lung ◽  
Jonathan Daniel Ip ◽  
Wan-Mui Chan ◽  
...  

Abstract A false-positive SARS-CoV-2 RT-PCR result can lead to unnecessary public-health measures. We report two individuals whose respiratory specimens were contaminated by inactivated SARS-CoV-2 vaccine strain(CoronaVac), likely at vaccination premises. Incidentally, whole-genome sequencing of CoronaVac showed adaptive deletions on the spike protein, which do not result in observable changes of antigenicity.


Author(s):  
Tapas Bandyopadhyay ◽  
Abhinav Sharma ◽  
Pratima Kumari ◽  
Arti Maria ◽  
Rahul Choudhary

Abstract Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-19) has emerged as a public health emergency in recent times. The reported data on the mode of transmission of coronavirus disease 2019 (COVID-19) are largely through contact, droplet, airborne and fomite transmission methods with vertical transmission being a rare entity. We hereby report a case of a probable vertical transmission of SARS-CoV-19 from an infected pregnant female to her neonate. The transmission has been confirmed by a positive RT-PCR at 16 h of life along with a positive IgG antibody test for SARS-CoV-19 in the baby and after excluding the possible environmental contamination of the sample. The baby was asymptomatic during the course of hospital stay and was discharged from the facility on Day 9 of life.


2021 ◽  
Vol 26 (40) ◽  
Author(s):  
Richard Molenkamp ◽  
Ewout Fanoy ◽  
Leonie Derickx ◽  
Theun de Groot ◽  
Marcel Jonges ◽  
...  

We evaluated routine testing with SARS-CoV-2 Delta variant-specific RT-PCR in regional hospital laboratories in addition to centralised national genomic surveillance in the Netherlands during June and July 2021. The increase of the Delta variant detected by RT-PCR correlated well with data from genomic surveillance and was available ca 2 weeks earlier. This rapid identification of the relative abundance and increase of SARS-CoV-2 variants of concern may have important benefits for implementation of local public health measures.


2021 ◽  
pp. 219256822110574
Author(s):  
Allen S. Chen ◽  
Matthew Brown ◽  
Anush Arekelyan ◽  
Sophie Wennemann ◽  
Nick Shamie ◽  
...  

Study Design Retrospective cohort study. Objectives The coronavirus disease (COVID-19), caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2), has created an unprecedented global public health emergency. The aim of the current study was to report on COVID-19 rates in an asymptomatic population prior to undergoing spine procedures or surgeries at two large Los Angeles healthcare systems. Methods Elective spine procedures and surgeries from May 1, 2020 to January 31, 2021 were included. Results from SARS-CoV-2 virus RT-PCR nasopharyngeal testing within 72 hours prior to elective spine procedures were recorded. Los Angeles County COVID-19 rates were calculated using data sets from Los Angeles County Department of Public Health. Chi-squared test and Stata/IC were used for statistical analysis. Results A total of 4,062 spine procedures and surgeries were scheduled during this time period. Of these, 4,043 procedures and surgeries were performed, with a total of 19 patients testing positive. Nine positive patients were from UCLA, and 10 from USC. The overall rate of positive tests was low at .47% and reflected similarities with Los Angeles County COVID-19 rates over time. Conclusions The current study shows that pre-procedure COVID-19 testing rates remains very low, and follows similar patterns of community rates. While pre-procedure testing increases the safety of elective procedures, universal COVID-19 pre-screening adds an additional barrier to receiving care for patients and increases cost of delivering care. A combination of pre-screening, pre-procedure self-quarantine, and consideration of overall community COVID-19 positivity rates should be further studied.


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