Coronavirus Testing
In the time of Coronavirus pandemic, many medical terms like RT-PCR, Antibody test, Antigen Test came into focus. There are different methods of testing and all the countries are experimenting to trace coronavirus. Rt-PCR (Reverse Transcription- Polymerase Chain Reaction) is the frontline test for Covid-19.
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Types of Coronavirus Test
RT-PCR
RT-PCR test stands for Reverse Transcription- Polymerase Chain Reaction. Majority of the tests that are conducted in all parts of the country are RT-PCR. It requires nasal and throat swabs that are directly used to identify the virus present in our body. This test can detect RNA (Ribonucleic acid) which is already present in the body before any antibodies or symptoms are shown. The test will transcript RNA to DNA by a process called reverse transcription before detecting any virus. The test material is usually taken from the upper respiratory tract i.e., from nose and throat, less often from the lower respiratory tract.
Process
The samples are collected from deep inside the nose and from the back of your throat with a swab. The sample goes through a chemical solution where proteins and fats are removed and the sample is only left with RNA. The sample is sent to a laboratory for analyzing and detecting the virus. This test can also detect the virus in an asymptomatic person, there is less chance of getting a false result.
Time
The exact time that RT-PCR test report will take to deliver is 3 hours, the maximum time they will take is 24 hours. The high amount of viral particles can be found in the respiratory tract during the first week of onset of symptoms.
When can a person perform the RT-PCR test?
According to doctor advice as soon as the symptoms are shown the patients should go for a test. If the person got positive for Coronavirus then they should be isolated and the persons who got in contact with him should be quarantined.
Limitation
- The virus is detected at the initial days of the infection.
- There is a chance of getting false results.
Antibodies Test
The antibody test is very fast and is less expensive. This requires the blood sample to examine whether our body has some antibodies for coronavirus or not. These antibodies are generated by the body and are used by the immune system to neutralize bacteria and viruses.
But the covid antibody tests are not 100% reliable. It is just a rapid test to detect the presence of the virus. If a patient got positive for covid-19, then they should undergo an RT-PCR test before the treatment. The antibodies production depends on various factors like age, nutritional status, and severity of the disease. The sensitivity depends upon the initial stage of Covid.
Process
Covid antibody test involves collecting blood samples from the hand. The blood is then examined by two types of antibodies IgM antibodies it shows the presence in an earlier stage and IgG antibodies which show later in a body.
Time
The covid-19 test results will come in 20-30mins and also is a low expensive procedure.
Limitations
- Antibodies appear late during the infection
- Presence of antibodies shows that a person is in contact with the virus.
- Chance of getting false results
Antigen Test
Antigen test is also used for detecting the virus in the body and not the antibody in a body. The ICMR has approved for using it in containment zones. The test is reliant on the nasal swab. The antigen is a toxin in the body that triggers the immune system. The samples that are collected from the nose and throat can show the result if a person is positive or negative. The antigen can be detected only in the early stage of the disease.
Process
The samples are collected from the Nasal which is found in SARS- CoV-2 virus. This test is performed outside the conventional laboratory setting.
Time
The maximum duration that it will take to show the covid-19 test report is 30mins.
TruNat tests
This test is commonly used for knowing if a person has tuberculosis and HIV, the principle is the same as RT-PCR but it has a smaller kit and the result is produced faster. ICMR confirmed this test for screening and confirming Covid-19.
Process
The TruNat machine is based on small and portable chips, also it runs on batteries. The virus has been detected in Nasal or Oral Swabs.
Time
The TruNat result will be provided in 60mins.
| RT-PCR | ANTIGEN TEST | ANTIBODY TEST | |
|---|---|---|---|
| Also known as | Diagnostic test, Molecular test, Viral test | Rapid diagnostic test | Serology blood test, Serology test |
| Sample collection | Nasal and throat swab test | Nasal and throat swab test | Blood sample |
| Covid-19 test reports | 24hours | One hour | 30mins |
| Need for second re-test | The test shows an accurate result | Positive results are accurate, For negative test go for Re-test | The second test is required for an accurate result |
| Test result | Diagnoses coronavirus infection | Diagnoses coronavirus infection | Shows the past result |
What if the patients test positive for Covid-19?
If a person is diagnosed with covid-19 then he is infected with active infections. Some effective steps to be taken to avoid the spread of Covid-19:
- Self-isolation
- Proper medication
- Boosting the immune system by taking proper diet.
- In case of severe symptoms like breathing problems or chest pain visit a Doctor immediately.
What if the patients test negative for Covid-19?
The person is not affected by the covid-19 virus but should follow the Covid-19 norms and guidelines. Follow some important guidelines like social distancing, wearing masks and hand washing. If it continues to show some symptoms, the doctor will advise you to take a retest.
COVID-19 test at Home
If a person is showing some symptoms of COVID-19 can consult a Doctor and take the Covid test at home. Mostly if the Doctor suspects you to be infected with Covid-19 he will advise you to stay at home and the health care personnel will visit your house to take the samples. You will be suggested to go through two kinds of tests i.e, RT-PCR and Antibody test. In RT-PCR the sample will be collected from the Nose and Throat and in the Antibody test your blood sample would be collected. After collecting the samples it will be taken to the laboratory where it will be examined and the Covid test report will be sent to you within 24 hours.
COVID-19 test at Hospital
Asymptomatic persons who do not have any symptoms but sometimes may be tested positive for Covid-19 can visit a hospital. During their visit to the hospital, the Doctor will advise them to go for an Antibody test where their blood sample would be collected. If they get tested for Covid they will be advised to take the RT-PCR test where the sample would be collected from Nose and throat. If they get confirmed for Covid-19 they will be advised to follow the Covid norms and are asked to self isolate themselves.
When should you get a Covid-19 test?
Persons with some common symptoms like fever, dry cough, tiredness, headache, loss of taste or smell, sore throat, body aches and pains can go for Covid-19 test. Some person who are asymptomatic i.e., do not show any symptoms can also take Covid-19 test. Mainly the virus incubation period is 5-7 days but sometimes it can be up to 14days. They will ask you to go through at least two kinds of tests i.e., RT-PCR and Antibody tests. Also, the person who has been exposed to the virus and has close contact with the confirmed Covid-19 case can take a Covid-19 test.
