Dr Gavin Jamie, a clinical researcher within the Oxford-RCGP RSC, is eager to share his knowledge and heighten awareness within the primary care sector. This month he is looking at SARS-Cov-2 and the importance of testing.
SARS-CoV-2 virus (an abbreviation of Severe Acute Respiratory Syndrome Coronavirus 2) was the cause of the global pandemic starting in 2020. Although we don’t know its precise origins it is probably the most studied virus that there has ever been. Its genome was rapidly sequenced, and the emergence of variants was reported widely in both the scientific and mainstream press.
In appearance it is very similar to other coronaviruses that have been detected for many years with characteristic spikes on the surface which it uses to attach to the cells of the respiratory tract which in turn causes many of its acute symptoms. These symptoms could vary enormously from the very mild to life threatening pneumonitis. Symptoms may also change or persist for extended periods of time – commonly described as Long Covid.
During the pandemic there was a mass testing programme of people with symptoms and some without symptoms with the intention of preventing the spread of the virus. There have also been national monitoring programmes by the Office of National Statistics.
Our monitoring preceded the pandemic and has included testing for the SARS_CoV-2 virus since the very start of the pandemic when it rapidly took over from influenza as the most detected virus in a majority of positive samples until the winter of 2021.
Our analysis looks at the RNA that forms the genetic code of the virus. The whole genome, like other coronaviruses, is very large so when testing swabs we look for two specific genes. Like a fingerprint finding these small areas allow us to identify the whole organism. The virus does mutate from time to time and unlike your fingerprints there is a chance of mutations changing one or other of these genes. Our tests are very specific so even a small change may produce a negative test. By looking at two genes we have a back-up allowing us spot even mutating viruses. This will not identify every mutation as we are only check small areas – the aim is to keep the test accurate.
We don’t know yet how SARS_CoV-2 will behave in the long term. Seasonal coronaviruses in the UK are more common in the winter, generally causing mild, if unpleasant, symptoms. In contract influenza produces waves of disease that vary from year to year.
In the 30 years that we have been monitoring viral spread we have not had the opportunity to observe the behaviour of a new virus before. A long term surveillance study such as this will give valuable information about how this virus is behaving and what we can expect in the future.