The novel coronavirus has ravaged through major continents, countries, and cities at a rate unprecedented in human history. 6 months after its emergence in Wuhan, China, the world has seen over 5 million positive cases and over 300,000 deaths. Countries like China, Spain, Italy, USA, Brazil and the UK have among the worst transmission rates in the world. This is owing partly due to climate, but mostly due to governmental policies, the responsiveness of governmental bodies, the standard of healthcare facilities, and overall cooperation of the nation.
The global atrocity, however, has forced countries and professionals to work together for a common cause in a way that we could not imagine in the past. Political differences, economical interests are brushed aside, in order for the whole world to focus on greater goals such as, containing the virus, enhancing healthcare facilities, discovering faster, more reliable tests, and developing a vaccine against Covid-19. Today, we are going to talk about how testing kits detect coronavirus (Covid-19) and the Covid-19 test procedure.
Generally, there are two methods used in detecting the Covid-19 virus. These tests use either the molecular method or serological method. The testing kits that are available on the market use the serological method. What that means is, it detects the presence of specific antibodies (immunoglobulin) circulating in the blood and tells you your status of infection.
Your body as a response to infection will release antibodies called IgM and IgG. IgM will be the first to be produced to fight off infection, and later, the IgG antibody will take over as the predominant antibody that fights off infection. These antibodies are able to recognise Covid-19 viruses from their surface molecules.
The test kits have specific molecules to detect these two antibodies and express its results through the appearance of different numbers of lines on the test kit, much like how a pregnancy test works.
The procedure is relatively simple and straightforward :
- 2-3 drops of fresh blood, serum, or plasma are collected and placed in a sample cassette.
- 2-3 drops of the provided buffer solution are added to the same cassette.
- Wait for the diluted sample to flow through the cassette
- The results can be read after 10 minutes and make sure not to wait longer than 15 minutes.
- The different combination of lines will tell you different results.
There are 3 lines, IgG (G), IgM (M), and control (C ) lines. The test is complete when the control line has appeared, meaning that the sample has flowed completely through the cassette.
The test is negative if only the control line appears and the other lines are not visible. This means that no antibodies against the coronavirus have been detected in the blood.
The test is positive if lines C and G, or C and M, or all C, G and M appears. Note that, the C must appear in all circumstances in order for the test to be valid.
A positive IgM (both C and M lines appear) means antibody IgM against coronavirus has been detected. The person is likely to be in the early stages of the disease.
A positive IgM and IgG (All C, M and G lines appear) mean both antibodies are present and the person is most likely in the mid-stage of the disease.
A positive IgG ( Both C and G lines appear) means antibody IgG against the coronavirus is detected and implies that the person is over the infection, or at its last stages.
From the above, we can conclude that the coronavirus testing kit is simple to conduct and easy to interpret. However, we need to clarify that this test cannot confirm the presence of Covid-19 virus in your system. What it does is, it tells you whether you have been exposed to the virus in the past or you have never been exposed to one. Therefore, using it on its own is practical only for screening purposes, and must be used in tandem with genetic testing to obtain a complete status of infection.