THIRUVANANTHAPURAM: As COVID-19 was confirmed in asymptomatic persons in the state, the demand for rapid tests are on a high. Usually, people with symptoms like fever and cough are candidates for the PCR test. The high cost of the test is one of the reasons why tests are not conducted on asymptomatic persons.

The test used now, called PCR (or polymerase chain reaction), uses a nasal or throat swab sample and identifies the virus. These tests take at least five hours to give results.

The rapid test, on the other hand, uses a blood sample and gives results based on detecting the presence of certain antibodies that react to the coronavirus protein.

Asymptomatic persons could carry the virus to another person. If tests are only conducted on persons with symptoms, the situation could get worse. Rapid tests are a solution to this. All individuals under observation can be tested for COVID-19 then.

Though the ICMR has given approval for rapid tests, kits are not yet available, says the health department.

In China, the reported source of coronavirus, there were 1541 asymptomatic persons confirmed with COVID-19, the National Health Commission said.