Rapid Antigen Test Kits recommended
On June 15, 2020, the Indian Council of Medical Research recommended the use of Rapid Antigen test kits along with RT-PCR in containment zones.
The Antigen test kits will allow faster diagnosis. They will reduce laboratory examination. The maximum time taken by the Rapid antigen test to interpret positive or negative is 30 minutes.
Recommendations of ICMR
According to ICMR, individuals that test negative to COVID-19 in rapid antigen test should be tested with RT-PCR. On the other hand, individuals testing positive under the rapid antigen test are considered to be positive.
Antigen Test Kits
The Antigen Test kits were developed by a South Korea based company SD Biosensor.
Why SD Biosensor kit was chosen?
The USFDA had earlier authorized US based antigen kit called sofia 2 SARS Antigen kit. Also, Japan had authorized the Fujirebio’s Antigen test kit. However, with tests and analysis conducted by AIIMS and ICMR, India was satisfied with the performance of SD Biosensor antigen kit. The selection was done based on the specificity and sensitivity of the kits.
The specificity of the test is 99.3% to 100%. The sensitivity of the test ranged between 50.6% and 84%.
What is Antigen test?
Just like the RT-PCR test of COVID-19, the antigen testing also looks for virus rather than the antibodies. Antigens are foreign substances that induce immune system in the body.
What is the plan?
The Antigen Test is to be used in three categories as follows
- Persons showing influenza like symptoms
- Asymptomatic patients hospitalized for the treatment of malignant disease, immunosuppressed patients, transplant patients, etc.
- Asymptomatic patients undergoing aerosol and surgical interventions such as surgical procedures, dialysis and bronchoscopy.
Limitations of Antigen test
According USFDA, the antigen testing is not as sensitive as that of RT-PCR testing. The sample collected for COVID-19 testing stays stable only for an hour. Therefore, its is essential to conduct the antigen testing at the site of sample collection.