BENGALURU: Karnataka, which has so far only used RT-PCR (Reverse transcription-polymerase chain reaction) tests on samples to diagnose COVID-19, will continue to do so for the next few days. The State Government’s plan to deploy the first set of Rapid Antibody Testing Kits at the district level from Wednesday will remain suspended.
The decision to suspend RTK testing came after the Indian Council of Medical Research (ICMR) advised states against testing for COVID-19 using RTKs for the next two days owing to complaints of faulty results. As of Tuesday evening, Karnataka had tested 26,233 samples for COVID-19 and all were done by the RT-PCR method.
Just hours before the ICMR’s directive, the State Government had distributed the newly-arrived RTK tests to the districts. The process of testing using RTKs was to begin from Wednesday.“The ICMR has validated my stand that RT-PCR is the only accurate test. I have consistently maintained that RTKs can be used only to detect antibodies after infection and isn’t very helpful in identifying the infection. Karnataka is already testing more than any other state in the country despite only using RT-PCR. We will continue to do that,” said Medical Education Minister Dr K Sudhakar.
Rapid testing not substitute for RT-PCR: Jayadeva chief
Karnataka is also locally validating samples of RTKs received earlier from ICMR at Nimhans. While the ICMR will conduct validation on the test kits received from China over the next two days, Karnataka will decide on further deployment of the kits after Nimhans’ validation test results. The RTKs will be deployed, if proven considerably efficient, only as an indication tool, and not for diagnosis. “The RTK is not a substitute for RT-PCR. Indication tests are different from diagnostic tests.
The RTKs are to be used on a separate set of the population for surveillance and quarantining purposes, and not for detection of acute COVID-19 infections. Using it for diagnosis/ detection of infection is wrong. The RTKs will throw up negative results if used for diagnosis because it takes about 10-14 days for antibodies to appear in the bloodstream post-infection,” pointed out Dr C N Manjunath, Director Jayadeva Insitute of Cardiovascular Sciences and nodal officer for testing in Karnataka.
He said that the RTKs can be used on individuals effectively only after 12 days of infection, but are handy tools to indicate community spread. “We are validating the RTKs. If the results indicate that sensitivity and specificity are acceptable, then we will deploy them,” he added. Karnataka may receive about 1.5 lakh RTK strips from two companies in China this week.