Thiruvananthapuram: Kerala is bringing about changes in the testing procedures to determine the prevalence of COVID-19 in the state, amid growing concerns that some parts of the state may be experiencing community transmission of the disease.
It has started antigen testing and plans to expand the use of antibody and CLIA tests also on suspected patients. The RT-PCR test will be used to confirm a case.
TrueNat, expert tests will continue at private hospitals and labs.
The antigen test will be done instead of the RT-PCR examination as part of the sentinel surveillance to ascertain contact cases of COVID-19.
At airports, returning expatriates will have to first undergo an antibody test followed by the antigen test instead of the RT-PCR and the CLIA examination for cluster testing.
The antigen test gives a result in 30 minutes and costs Rs 450. However, its accuracy rate is low.
CLIA will be used instead of serosurveillance and rapid antibody tests to ascertain community spread.
CLIA will also be used instead of RT-PCR in epidemiological studies to determine the source of infection.
The CLIA test is a variant of the Elisa test. Blood tests are done to determine the presence of antibodies. If rapid antibody tests are to be done using test strips, then the CLIA sample will be sent to labs. The test costs about Rs 500.
Tests at the airport
Kochi: At airports, if antibody examination turns positive, then the antigen test will be conducted instead of RT-PCR to confirm COVID cases. This is because the results of RT-PCR tests take a long time to come.
If there are COVID-like symptoms, the passenger will be shifted to primary COVID treatment centres or COVID hospitals. They will then be put through the RT-PCR test. If the result is positive, the patient will have to continue at the hospital, and if it is negative, the passenger will be moved to a quarantine centre.
The antibody test will be conducted on passengers with no symptoms. If the result is negative, then the passenger will be put under quarantine. The antigen test will be conducted in cases that are positive.
Again, those whose results are negative will be put in quarantine. Those who test positive will be first moved to the primary COVID treatment centres or COVID hospitals and later to the hospitals at their respective districts.
Antigen test accuracy rate is just 10%
The antigen test is not fruitful in fighting COVID and other states have stopped using it, health experts have said.
Tamil Nadu was the last state to drop it; it abandoned the method on June 27.
The only good thing about antigen testing is that the kit costs only Rs 450 against the Rs 2,500 for the PCR kit. However, the accuracy rate of the antigen test is only 10%. Health experts, therefore, dismiss the claim that the antigen test is more cost-effective.
