COVID-19 TESTING SYSTEMS EXPLAINED
PCR TESTING: The most sensitive test that is currently available, able to detect active infection some days before the patient is infectious or symptomatic.
It is the gold standard test; used in the NHS daily. PCR testing takes around five hours to be performed, but as tests sometimes have to be repeated, a turnaround time of 24 hours is often given. PCR testing is performed in machines then cycled through different temperatures. As the process of changing temperature takes some time, it takes longer than other processes such as LAMP.
LAMP TESTING: Another form of genetic test, able to detect the RNA of the virus. It is a more recent development than PCR and is performed all at one temperature.
It is generally faster and cheaper than PCR but is not considered to be as sensitive – but is still more sensitive than antigen testing. LAMP tests might be able to detect patients immediately before symptoms are displayed but this is unsure at present. Rapid LAMP testing can add a significant degree of confidence if performed before flying, for example, when all aboard have had a LAMP test prior to departure. ANTIGEN TESTING: The fastest and cheapest of all lab tests for Covid-19. Antigen tests often become positive after having had symptoms for a couple of days. Their use is particularly powerful when patients are attending communal events and a quick check needs to be performed to see if attendees are infectious with Covid-19. Also during winter months, when people often have symptoms of the common cold or flu, performing an antigen test will ascertain whether the condition is the coronavirus or not.
ANTIBODY TESTING: This is a test that looks for the presence of virus antibodies in the system. The presence of antibodies indicates that the patient has previously had Covid-19, as their body has developed the antibodies necessary to fight off the virus. However, a lack of antibodies does not indicate that the person has not had Covid-19, as not every patient develops them, and much is still to be understood about how long the antibodies last in the patient’s system.