Amid Coronavirus outbreak, one of the key factors in tackling the spread of the virus across the globe is testing. In South Korea, mass testing has been used to try and quickly identify and isolate those who are infected with the disease. Testing can prove to be vital in calculation of accurate infection and survival rates, data that is critical for getting public safety measures right.?
And as this Coronavirus outbreak is still going on worldwide, people are being tested?and a lot of new test kits are being developed.?
There are two main ways to test for infection with SARS-CoV2 - the virus that causes COVID-19 disease. The first way is to do a sensitive test that looks for the RNA of the virus by using a technique called RT-PCR. This can detect as little as one virus from the test taken from the inside of the mouth or nose.?
A second type of test which measures the antibody responses to the viruses in the blood.?
Some antibodies are very useful that help in killing the virus or to stop infection, some help in binding the common parts of the virus but are unable to defend it.?
The test is simple, coat a test tube with a virus ¡°mash¡± or ideally purified virus components then add a tiny amount of a very diluted blood sample of the patient and let antibodies bind the test tube. Finally, develop the test to see if any antibodies are present.?
When the disease came to Wuhan China, most of the other countries relied on RT-PCR tests because these were fastest to develop.?
More antibody tests are now becoming available to the public which will help in reporting the exact number of cases. The UK have been very quick in developing an RT-PCR test and this remains the primary method, they are evenly using the network of labs for the same. This eventually helps in getting consistent data but has stretched capacity from the vast scale of the outbreak.
RT-PCR is a very specific and sensitive test but it's also said that the tests can no longer tell if you¡¯ve been infected. if someone has self-isolated themselves due to mild fever cough. RT-PCR tests need a laboratory to perform as it takes time. The machine called Rapid portable RT-PCR that is cutting edge of the diagnostic technology and the COVID-19 tests are becoming available for these only. These even the fastest machines take around two hours. These have been evaluated in the National Health Service to improve flu treatment.?
Antibody typically takes a few weeks to develop against a new infection and lasts much longer in the blood than the virus itself, if you have any pre-existing disease record or on going.?
The current antibody tests for the coronavirus haven¡¯t been fully tested so they're not absolutely reliable. WHO has also shared guidelines which recommend RT-PCR testing. The government of the UK has announced that it had ordered for 3.5 million home tests that could soon become available for NHS workers once they get validation. Testing for viral infection hasn¡¯t been widely used in the UK before and these types of test are not easy to use. Saliva - based antibody testing might be possible, but we have even less data than for blood serum.?
While the concept of an antibody test is well established, there are multiple challenges in making and using them. Unlike RT-PCR, antibody measurement takes time to refine and needs viral components to be produced than that has to be purified. In order to check these tests are useful, very collective sets of patient samples are needed.?
An antibody test must be checked with many different samples, not only to understand accuracy but to also know how long it would take after infection of the person becomes positive. However it is also required to check for how long it stays positive after the patient has recovered.?
What is better Lab testing or home testing kits??
Rapid tests - that work like pregnancy tests on the other hand they are faster and cheaper too but have less accuracy than the lab tests.?
In simple terms, these tests are usually run through a modified paper which stats one line for negative and two lines for positive. These tests are quick to manufacture and are typically easy to use but have to be carefully designed and validated by the right source.?
As with vaccines, it¡¯s vital that any test is accurate and safe and that it takes a lot of time and money. If the test seems inaccurate then that could cost us lives of humans involved with that one person. Some tests which are used have the accuracy of about 80 per cent. This has been intensively studied for many important and vital infections.?