COVID- 19 tests
The novel corona virus disease that was first identified in Wuhan has received an official name from the World Health Organization (WHO) as COVID-19 and the virus is named as SARS COV 2. COVID 19 has been declared by WHO as pandemic affecting many countries, including ours. Incubation period of COVID 19 may range from 2-14 days and symptoms may include fever, cough, shortness of breath etc in varying severity. The predominant routes of transmission include droplet and contact.
The uses of vaccines help in fighting against covid 19 and reduce the spread of this deadly virus.
COVID 19 test:
There are different types of diagnostic tests available. Some diagnostic tests detect infection and others detect an immune response. There are principally two types of tests available for COVID-19: viral tests and antibody tests. The viral tests are direct tests as they are designed to detect the virus and therefore reflect current infection. In contrast, the antibody tests are indirect tests, as they do not detect the virus, but rather ascertain established seroconversion to previous infection, or early seroconversion to ongoing infection.Testing plays an important role in a public health response to COVID-19.
Why is COVID- 19 tests prescribed?
Your health care provider may order a COVID- 19 test in certain conditions:
- Presence of symptoms such as fever, cough, tiredness, or shortness of breath.
- You don't have symptoms, but you've had close contact with someone who tests positive for the COVID-19 virus or is suspected of having the virus.
- You've participated in activities that increase your risk of COVID-19 — examples include travel, large gatherings or crowded indoor settings.
- Your doctor or other health care professional or your public health department recommends a test.
What are the components of this test?
There are two types of COVID- 19 test-RT-PCR , Antigen detection and Antibody test:
Diagnostic test-There are different types of diagnostic tests available. Some diagnostic tests detect infection and others detect an immune response.
Molecular test
- RT-PCR test : Also called a molecular test, this COVID-19 test detects genetic material of the virus using a lab technique called polymerase chain reaction (PCR).
Serological test : Serological testing detects antigens and antibodies directed against the virus.
- Antigen test : This COVID-19 test detects specific proteins on the surface of the virus.
- Antibody test : This identifies antibody formed against COVID- 19 virus ,it does not detect active viral infection.
Procedure and prerequisites
ANTIBODY test is done from blood sample. For that a small needle is inserted into vein of your arm. A small amount of blood is then collected in test tube or vial. You may feel little pain due to needle prick. No special preparations are required for this test.
RTPCR AND ANTIGEN test are done by collecting swab samples from nose or throat. Doctor or other health care professional inserts a thin, flexible stick with swab at the tip into your nose or brushes the swab along the back of your throat to collect a sample of mucus. This may be somewhat uncomfortable. The different types of these samples according to their location are anterior nares, mid-turbinate, nasopharyngeal and oropharyngeal. Saliva samples are sometimes collected by spitting into test tubes rather than using nose or throat swab.
Reference range
Viral test: Positive result: This means currently have an active infection with the virus that causes COVID-19. Negative result: This means that likely weren't infected with the COVID-19 virus.
Antibody test: can be positive (presence of antibody against virus) or negative (absence of antibody against the virus)
