RAPID ANTIGEN TEST : HOAX OR SOLUTION ?

The rapid antigen is a test that detects antigens (foreign compounds that induce an immune response in the body) located on or within the SARS-CoV-2 virus using swabbed nasal samples. It's a point-of-care test that's done outside of a traditional laboratory setting to get a speedy diagnosis. The Indian Council of Medical Research (ICMR) has approved the use of antigen detection kits created by S D Biosensor, a South Korean business with a manufacturing facility in Manesar. The kit includes a Covid antigen test gadget, a viral extraction tube with viral lysis buffer, and a sterile swab for sample collection.

The gold standard frontline test for the diagnosis of Covid-19 is now RT-PCR. The rapid antigen detection test, like RT-PCR, aims to identify the virus rather than the body's antibodies. While the mechanisms are distinct, the most fundamental distinction between the two is time passage.

According to the ICMR, the RT-PCR test requires a minimum of 2-5 hours, including sample transportation time. The ICMR advisory notes, "These limitations limit the general adoption of the RT-PCR test and also impede speedy augmentation of testing capacity in various containment zones and hospital settings." The maximum time for evaluating a positive or negative test in a valid fast antigen detection test is 30 minutes.

According to ICMR rules, a positive test result should be genuinely positive and not require confirmation. Those who test negative for rapid antigen should be screened for infection using RT-PCR.

The US FDA noted that antigen tests are fairly specific for the virus. However, they are not as sensitive as molecular PCR tests when they are granted emergency approval for the first antigen kit. "This means that positive antigen test findings are quite accurate, but false negatives are more common; therefore, negative results do not rule out infection." With this in mind, negative antigen test findings may need to be validated with a PCR test before treatment decisions are made or prevent the virus from spreading due to a false negative, according to the USFDA.

Pravalika Reddy is a Media Studies student at the University of Hyderabad. She writes about body positivity, science and tech for 'The Pigeon'.