NEW DELHI: A day after ICMR said it has asked states to stop using rapid testing kits for Covid-19 for two days so that it can check complaints, they have been told to continue using the antibody diagnostic kits for surveillance and monitoring trends as per protocol prescribed by the Indian Council of Medical Research (ICMR).In a letter to state chief secretaries on Wednesday, ICMR additional director general G S Toteja said, “States are advised to follow the prescribed protocol for these tests and use it for the purposes for which these are meant. lt is reiterated that to contain Corona Virus infection, RT-PCR tests must be continued vigorously as the principal diagnostic tests.”The ICMR reference to the polymerase tests underlines that they are the “gold standard” for detecting Covid infections and shows that states were not following the protocol that rapid tests are not for diagnostic purposes.ICMR reference shows that states were not following the set protocol that rapid tests are not for diagnostic purposes. TOI had reported about the issue in its edition dated April 22.Following complaints that the antibody test kits are showing varying levels of accuracy, ICMR on Tuesday said it has advised the tests be suspended pending field validation and investigation by its teams.However, forwarding a protocol on use of rapid antibody tests to states on Wednesday, ICMR asked them to use it as a tool for surveillance and not to diagnose Covid-19 cases.“I would again reiterate that antibody rapid tests are largely to be used as a tool for surveillance with respect to formation of antibody in persons exposed to the virus. Globally also, the utility of this test is evolving and it is currently being used for detecting the formation of antibodies in individuals. These test results are also dependent on field conditions,” the letter from Toteja said.The medical research body has told states that the test kits cannot replace the RT-PCR test. To further assist states, ICMR will collect data from various states to assess the scope and extent of utility of these rapid antibody tests in field conditions.Senior officials said the decision to continue using the kits was taken at a high-level meeting on Wednesday. “We evaluated the feedback from the states. These kits are not meant for diagnosis of Covid-19 but only for surveillance. States are required to follow the ICMR protocol properly. Meanwhile, we will investigate it based on data collected from states,” an official said.India had taken delivery of 500,000 rapid antibody test kits from China last week. Besides, some states have also separately procured such kits. Till Wednesday, the health ministry reported a total of 19,984 confirmed cases of Covid-19 along with 640 deaths, which included 50 new deaths in the last 24 hours. Also, 3,870 people have been cured with a recovery rate of 19.36%.