Influenza, Covid or RSV? The emergence of combined testing options
The flu season is well and truly upon us, but is it Influenza, RSV or Covid? And does it matter? The 'tripledemic' season of Influenza, COVID-19, and RSV viruses Influenza A/B, COVID-19 with its variants and respiratory syncytial virus (RSV) are the three largest contenders responsible for respiratory infections globally. The European Centre of Disease prevention and Control and the Pan American Health Organisation have reported unusual infection spikes this year, collectively...
Using COVID-19 serology status to inform vaccine prioritisation
Global vaccine roll out is making progress but with most countries wanting priority status and with a limited supply, how can governments best prioritise those requiring vaccination? Vaccination strategies Overall two vaccination strategies are in place: the first concentrates on those at highest risk, the second focuses vaccinations on people most likely to transmit the virus, known as direct and indirect vaccination strategies, respectively. Regardless of vaccine type and manufacturer, there are...
To rapid test or not to rapid test for COVID-19
As the pandemic has struck the predicted second wave, public struggles persist with lifestyle restrictions, but our knowledge to identify and fight the virus has significantly progressed. With tests developed, distributed and administered satisfactorily for most symptomatic sufferers (PCR), and the vaccine roll out for the most vulnerable, science and medicine turn to consider the silent carriers of SARS-CoV-2…the asymptomatic vectors. The case for rapid antigen testing using Lateral Flow At present testing...
Six examples of COVID-19 mass testing events
From the outset of the COVID-19 outbreak, testing for SARS-CoV-2 has been a priority. Initially just having a test for COVID-19 was a scientific success, enabled by the publication of the first viral genomic sequence in January 2020. As the pandemic has run its course many aspects of testing have been investigated. Here we highlight some of the key testing events that have taken place, and their outcomes. Mass Covid Testing -Vo’,...
SARS-CoV-2 – The value of Ct values
What are Ct values? In quantitative PCR (qPCR) and reverse transcriptase quantitative PCR (RT-qPCR), the cycle threshold (Ct) value is the number of nucleic acid amplification cycles required for the signal generated by the amplification of a specific target DNA to cross a set threshold. Labelling the DNA primers with a fluorescent tag is what makes this PCR ‘real time’; as the target genetic material increases with each amplification cycle...
Swabs and COVID-19 – A Guide
This article covers swab type and selection, transport products and medium enabling a smooth transfer of patient samples to the laboratory for analysis. Additionally, we discuss the implications of cycle thresholds and whether they should be assessed in patient prognosis. Swabs Swabs come in all shapes and sizes and some favourites have become well known in recent months: Nasal Swab: needs to be inserted at least 1cm into the naris (nostril), directed...
The utility of SARS-CoV-2 IgA in COVID-19 testing
At the outset of the 2019 SARS-CoV-2 / COVID-19 epidemic, diagnostic immunoassay manufacturers focused on developing anti-SARS-CoV-2 IgM & IgG tests. While the epidemic has progressed to become a global pandemic, diagnostic test developers’ efforts have also evolved. Recently, we have noticed an increase in interest for patient material positive for Human anti-SARS-CoV-2 IgA. This article will take a look at the difference between the different immunoglobulin sub-classes and seek to...
Infection with the “other” human Coronaviruses could be a blessing in disguise
With the world’s attention focused on SARS-CoV-2 and the serious impact COVID-19 is having both on our health and on society as a whole, it is worth noting that humans have in fact co-existed with numerous coronaviruses (CoVs) for millions of years. It is little understood how these related viruses have such startlingly different effects on infected individuals but some researchers have found evidence that mild CoV infection offers some...
The best sample type for SARS-CoV-2 virus rapid tests will surprise you!
Two types of tests for SARS-CoV-2 currently predominate. The first are molecular tests, based on PCR technology, that detect the presence of viral nucleic acid and therefore indicate a current infection. The second are serology tests that are designed to detect anti-SARS-CoV-2 antibodies (usually IgG) generated by the immune systems of individuals who have been infected in the past. RT-PCR to detect SARS-CoV-2 virus is relatively slow and requires specialist laboratories....
SARS-CoV-2 – Beware Antibody Tests with <100% Specificity
We are in the midst of the most significant global pandemic since the 1918-19 Influenza pandemic, over 100 years ago. The 2020 pandemic has been caused by a Coronavirus, named SARS-CoV-2, which confers a severe respiratory illness (COVID-19) on a proportion of those infected. The virus is readily transmissible from human to human with many of those infected showing no or mild symptoms, meaning it is hard to know who...
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