Preventive Health Care

How do Testing Kits of COVID-19 detect the Virus?

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The most destructive pandemic of all times is still raging above us and we are all at the mercy of precautions.

But testing of immediate contacts of any positive COVID-19 patients is equally necessary. Testing also becomes very important in the case of asymptomatic people.

COVID-19 test is a long process and requires special types of equipment that does not come cheap. It also requires a great deal of labor to carry out the test. There are two types of tests involved in COVID-19 namely

Viral and Antibody

The viral test tells whether a person has a current infection and an antibody test shows if a person had a past infection. An antibody test will not be able to tell if a person has a current infection.

But the story of COVID Tests isn’t that easy. People still do not have a clear idea about the procedure of getting CORONA tested. There were many speculations about where to get tested and how much will the COVID Test cost?

Until two months back all the COVID-19 tests were done by govt. health departments.                            

On April 8, the announcement for making the test of novel Corona virus-free at approved laboratories was made. The reimbursement would be done or not would be considered later.

This announcement didn’t go easy on the private sectors of a country with the second-highest population. An amended notice which entailed free tests for people under government flagship program Ayushman Bharat was issued and the rest of the people will have to pay for the test.

Private labs were open to charge a fee that didn’t exceed a fixed mark set by the government from people who could afford it. This limit was INR 4,500. Now the most recent update on COVID-19 test cost is about INR 2500 for most cities. In some states, it is INR 2400.

Now the mechanics and statics of COVID-19 tests in India are continuously under scrutiny and debate. The test is taken several times to ensure proper recovery in patients so this amount cap is how much feasible is still discussed.

Also in cases of past traveling records, people have to get tested without any symptoms and that compromises a large group so again amount cap is under scrutiny.

The prices as said by ICMR are based on the cost of the special kit used to test COVID-19 infection. The COVID-19 test is done on two levels:

Screening test- the presence of any corona virus-related bacteria in the swab of the patient is tested.

Confirmatory test- the presence of the novel virus is tested in the patient. This test is done if screening tests are positive.

In private labs, a single sample is used to test both screening and a confirmatory test.

Now let’s look at the process of detection of the COVID-19 virus.

How do testing kits of COVID-19 detect the virus?

India like many others is using RT-PCR for the detection of coronavirus. This is Reverse Transcription polymerase chain reaction.

It’s a kind of chain reaction to amplify the DNA enough for its evaluation. There are certain methods to extract the DNA from the sample.

Reverse transcription is used to extract DNA by treating samples with chemicals.

Starting from the extraction of a single-stranded RNA from the sample and encompassing an enzyme to convert the RNA to a double-stranded DNA which is called the reverse transcription.

Now the DNA is tested in a tube with a DNA of target novel coronavirus through binding them. This is followed by a process of multiple cycles of heating and cooling to amplify the DNA.

A fluorescent detector that makes the DNA glow identifies the virus.

This process requires a few hours. With increasing rates of suspects in a humongous population, we don’t have much time to spare.

So, a time-saving version is real-time RT-PCR (qPCR). It gives advantages like automation, reliable instrumentation which makes it more preferable.

Samples for the tests are taken through nasopharyngeal swab, throat swabs, saliva, and sputum or coughed up material or material collected via a suction catheter.

Process of COVID-19 RT-PCR test:-

Samples from deep inside of your nose and throat are collected and worked upon with some chemical solutions that help in removing fats and proteins from the sample and the final result is just the RNA of the sample. This RNA sample is then sent to a laboratory where the analysis with the RT-PCR machine is carried out to detect the COVID-19.

The test is carried out twice on the patient to confirm the presence of a virus. Because in 30% of the cases, the RT-PCR test has shown false results. Although the test is can even diagnose the presence of Coronavirus in asymptomatic patients as well.

The cost of RT-PCR tests for COVID-19 is around 2,200 to 3,000 in different states.

Other tests for COVID-19

Although the RT-PCR test for identifying COVID-19 stays as the gold standard for testing the virus, the Health Ministry has also come up with a few other tests to identify the virus. The types of testing kits have gradually expanded with different testing strategies. There are other types of COVID-19 tests other than RT-PCR namely- antibody test, antigen tests, TrueNat, and CBNAAT. These tests were introduced to combat the increasing requirement of testing in the country.

Dr. B. Lal Clinical Laboratory Pvt. Ltd. was established in 1991 with a motive of Serves Best, Serves All and since then it has been working uninterrupted to provide Pathological and Diagnostic solutions that incorporate the best infrastructural and technological advancements in the world of the health sector. Our passion is to deliver the best quality healthcare services combined with the uncompromised trust shown by doctors and patients in our services have made us a distinguished preference over the last 30 + years.

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