Why in News?

SalivaDirect, a new rapid diagnostic test for novel coronavirus infection that uses saliva samples, was granted an emergency use authorization by the U.S. Food and Drug Administration (FDA).

News in Detail

• The test uses a new method of processing saliva samples for testing coronavirus infection.
• It is an easy, inexpensive SARS-CoV-2 testing.
• The test has a high sensitivity (ability of a test to correctly identify those with the disease (true positive rate)) of about 93%.

Advantages of saliva test

• Instead of relying on nasopharyngeal specimens, the new test uses saliva, which makes the sample collection non-invasive. 
• It also reduces the need for trained healthcare workers to collect the samples and reduces the risk of virus spread to healthcare workers at the time of sample collection. 
• This is because collecting the sample from the nasopharyngeal region requires a swab to be inserted into the back of the nostrils, which very often causes irritation leading to sneezing and coughing, thus exposing healthcare workers from getting exposed to the virus.
• Collecting nasopharyngeal samples can be uncomfortable to people, discouraging them from getting tested. The saliva test is likely to increase testing compliance.
• Saliva testing could allow for at-home, self-administered sample collection for accurate large-scale SARS-CoV-2 testing.
• The diagnostic test also does not require the use of preservatives at sample collection, does not require specialised reagents or equipment for nucleic acid extraction. 

Reference:

1. https://www.thehindu.com/sci-tech/science/fda-approves-rapid-inexpensive-saliva-test-for-novel-coronavirus/article32366694.ece