Types of covid tests. Which test should you take and why?
There are two main categories for covid19 testings.
- Viral and
- Antibody test
Viral test t will let you know if you have current infection
Antibody test wil let you knoew if you have had an infection.
The covid19 virus is made up of proteins and RNA
Test types:
Viral tests can be calsiffied into two depending on the puspose of the test. RNA and RT_RNA
- Rapid ANtigenTest
Specimen: Nasopharyngeal swab
This test will look for antigen (protein) of covid 19 virus
Nasal samples are collected and tested for antigens that are found in the SARS _CoV-2 virus. the test s can be done outside the laboratory and provide quick results.
This type of test is a rapid chromatographic immunoassay fot the qualitative detection of specific antigens to SARS-CoV-2 present in the human nasopharynx. It also provides only an initial screening test result. More specific alternative diagnosis meathods should be performed in order to obtain the confirmation of SARS-CoV-2 an infection like COVID 19 PCR
Negative reslults in a sumptomatic person require further RT PCR/CBNAAT/TRUENAT test.
A negative result may occur if the concentration of antigen in a spoecemn is bnelow the detection limit of the test. therefore a negative test reult does not eliminate the possinility of SARS-CoV-2 infectin. and should be confirmed by COVID RT PCR.
2.Real-time PCR
Specimen: Nasopharyngeal / oropharyngeal Swab
This test will look for Nucleic acids ie. RNA of Covid-19 virus. This particular test is performed by collecting a sample from the patient’s nose or from the back of the patient’s throat with a swab and then it is treated with a chemical solution that removes the proteins and fats revealing only the RNA present in the sample where RT PCR machine is used for detecting the virus.
TRPCR ( Reverse Transcription Polymerase Chain Reaction) This is a molecular test whichu lools for the genetic material of the virus.
Rela tTime- PCR test is intended for the qualitative detection od nucleic acid from the 2019-nCoV n upper and lowe respiratory specimens collected from individuals who meet 2019-nCoV clinical or epidemiological criteria.
3. TruNAT
Specimen: Nasopharyngeal / oropharyngeal Swab
This test will look for the RdRp enzyme found in the RNA of Covid-19 Virus. The machine will detect the RdRp enzyme found in the virus in nasal oral swab
TruNAT test works on the same principle as RT_PCR but it has a smaller kit and produces quick faster nad more realiable result. TrunAT is also used to detect tubercolosis, HIV other than COvid.
Antibody test
The antibody test will detect antibodies produced by the body’s immune system in response to SARS-CPV-2
COVID19 serology test can tell if you have had the viral infection in the past. but this test is not the preferred test to detect current infections as antibodies do not show up for about 1-2 weeks hence the quarantine.
Important knowledge about Corona Virus
Corona virus are non segmented positive stranded RNA viruses with a roughly 30kb genome surrounded by a protein
The virus have an envelope of about 80-120 nm in diameter
Most virus casus diseases in their particular host species, those that can infte human though cross species transmission have become an important treat to public health