As we finish yet another week of lockdown, in India, we have fortunately moved into the phase of testing, testing, testing, for the coronavirus.
Why is this important? The testing can give us a good idea of how badly this virus is really affecting us.
With testing, we can identify those affected, trace who they might have infected around them, isolate these people, see how we can treat them, and try to get a handle on the spread of the virus. We can even use this to see when different countries can loosen lockdowns. This data can be used to decide which people can go home to different states, to design drugs against the virus, and to build the appropriate health policies and infrastructure for those affected.
What are the kinds of tests that are available for testing for the coronavirus?
- RT-PCT test – this is a real-time PCR test, been used for many years to analyse DNA. This is the Gold Standard for detecting the virus. The virus is an RNA virus, but not an issue, because you first stick an enzyme (catalyst) into the reaction that reads and converts the RNA strand into DNA, then the PCR test amplifies or creates many copies of the DNA, to create a sample rich in this specific sequence of DNA.
When you study the DNA that comes out of the PCR reaction, you are looking for sequences that only the virus genome has. These sequences are not found otherwise in humans, even those who have suffered from other viruses like the cold. So a positive test here means you have the coronavirus, and a negative one here means that you don’t. Not right now anyway!
- An antibody test – if a person has been infected with the coronavirus and they have recovered, their bodies will have launched an immune attack against the virus, and will have generated antibodies against it. These fight and neutralise threats. Therefore, you can test for the presence of antibodies in the blood to see if the person is infected or has been infected before. These antibodies can be detected days 10+ days after getting the infection, in about 80% of the people. It cannot be used for diagnosis, but to detect if a person has been exposed to the virus. So at this stage, antibody tests, once developed and accurate, can be used to test people’s blood to see who has come into contact with the virus.
Why has testing been in the news so much? Testing is the only real way to get a handle on the infection rate and how strong the virus is. It plays an important role in screening people, separating the sick from the healthy, and to try and prevent the spread of the virus.
Because so many companies have made a huge effort and rushed to get their tests approved, some of them still need to be properly checked so that the regulatory authorities can say which ones are the most accurate.
Now that India is conducting more testing, we might see the numbers of those infected go up. Don’t worry – we weren’t testing before, so the numbers can only go up! Understanding the beast you are trying to duel is important, and we are starting to collect important information that can help us fight effectively.
Written by: Sunaina Murthy. Sunaina is a biotechnologist, greedy reader, and amateur photographer.