Showing posts with label RDT. Show all posts
Showing posts with label RDT. Show all posts

Thursday, June 11, 2020

Corona test: What are RDT and PCR?

Two methods of corona testing

The Kovid-19 epidemic has affected millions of people. Effective treatment is being sought, but not yet discovered. The spread of the infection has been rapid in Nepal recently. Complaints are growing in Nepal that the test itself is not effective.

There are two methods of corona testing in Nepal to find out if a person has a corona infection - PCR and RDT.

What is PCR?

PCR (Polymerized Chain Reaction) is a modern technology for detecting the genetic genes of a bacterium. It is being used to find out if there is a coronavirus infection in the body. PCR is used to test the protein by extracting a swab (nasal or throat fluid) sample.

The PCR method quickly copies millions to billions of specific DNA samples. This will help scientists to take the smallest sample of DNA and study it in detail. PCR was invented in 1983 by American biologist Kerry Mullis at Sets Corporation. This is the basic method for genetic testing, including analysis of old DNA samples and the identification of infectious agents. PCR has now become a common and often indispensable technology, used in medical and clinical laboratories in a wide range of research in biomedical medicine and criminal forensics.

Simply put, PCR detects viruses in the body. Therefore, it is considered reliable for coronavirus testing. According to experts, the PCR test is best done within 10 days of the week of infection. After 10 days, the actual results may not come from the PCR test method.

PCR helps to detect any bacterium, not just the corona. Its main function is to detect the gene of the target bacterium. This method has been found to give more than 70 percent correct results.

What is RDT?

RDT (Rapid Diagnostic Test) is a medical diagnostic test, which is quick and easy. It is used for initial or emergency medical examination. Blood is drawn from the body and the test results can be seen in 20 to 25 minutes.

It is being used to detect disease-fighting antibodies in the body. Corona's RDT test is not effective in Nepal, raising questions about its reliability. The WHO also does not consider this method reliable for corona testing. Experts say that it is best to use it only for general surveys.

Different results of RDT and PCR

The results of RDT and PCR in Nepal so far have been very different. Why does this happen? Infectious Diseases Specialist of Shukraraj Tropical and Infectious Diseases Hospital, Dr. According to Sher Bahadur Pun, the results also depend on the time of testing of the infected. He says, ‘RDT only shows up after about 12 days of infection. It does not show if you have just been infected. The PCR shows up when checking. '

He says the type of antibody also varies with the test results. There are two types of antibodies, IGN and IgG. If IGN is seen, it means that there is a new infection. It appears on the PCR ', he explains,' IgG may not show on the PCR. As it appears after about two weeks, it does not appear on the PCR test. '

According to him, the PCR test is positive in the newly infected person and the RDT is negative. However, testing 10 days after infection can show PCR negative and RDT positive.

(With agency support)