India procured five lakh rapid antibody testing kits from China last week and these were distributed to states for the districts with a high burden of the infection. (Photo: K Asif/India Today)

The Indian Council of Medical Research on Tuesday told states to stop using the newly-distributed Chinese rapid testing kits to detect coronavirus for the next two days after huge variations in the accuracy of results were noticed across regions.

Addressing its daily briefing on Covid-19, head of Epidemiology and Communicable Diseases at ICMR Raman R Gangakhedkar said, "We got a complaint of less detection from one state. So we spoke to three states and found that a lot of variation is there in the accuracy of test results of positive samples, in some places it is 6 per cent while others it is 71 per cent."

"This is not a good thing because when such a huge variation is seen we need to investigate further even if it is the first generation of the test. This disease is only 3.5-month-old so all technologies will be refined over time but we can't ignore these findings," he added.

He added that over the next two days the ICMR will be sending eight expert teams on the field to validate the results.

"Hence, all states are requested to not use the rapid testing kits on the field for the next two days," Gangakhedkar said.

The ICMR also said it will raise an issue with the manufacturer of the kits if results continue to be faulty.

Earlier on Tuesday, the Rajasthan government stopped using the China-made rapid testing kits for coronavirus after they delivered inaccurate results.

The state's health minister Raghu Sharma said the kits gave only 5.4 per cent accurate results against the expectation of 90 per cent accuracy and therefore the kits were of no benefit, adding that the Indian Council of Medical Research (ICMR) has been informed about the issue.

The ICMR had also received complaints related to repeat testing of patients in West Bengal as the RT-PCR kits were not working properly.

India procured five lakh rapid antibody testing kits from China last week and these were distributed to states for the districts with a high burden of the infection.

The rapid testing kits, through which blood samples are tested, were aimed at speeding up screening and detection of suspected coronavirus patients as they take less time to show results in comparison to the swab-based tests carried out in pathology labs.

This is different from the RT-PCR kit which are currently used for confirming cases and rely on molecular data. The RT-PCR test is the gold standard for frontline test for Covid-19. The rapid kit test was not a confirmatory test and PCR based test was required for confirmation of a positive result.

The rapid antibody test kits procured are not meant for early diagnosis, but only for surveillance and trend checking and are US FDA approved.

Correction: A previous version of this copy mistakenly identified the rapid antibody testing kits as the RT-PCR kits. The error has now been rectified.