New Delhi, Apr 27 (IANS): The Indian Council of Medical Research on Monday directed states to stop using rapid antibody test kits procured from China-based Guangzhou Wondfo Biotech and Zhuhai Livzon Diagnostics after their results showed wide variations.

The statement came several states raised concerns over performance of tests during the exercise that they undertook.

Following the complaints, ICMR said it evaluated the kits of the two firmsin field conditions. "The results showed wide variation in their sensitivity, despite early promise of good performance for surveillance purposes," it said in a statement.

"In view of this, states are advised to stop using these kits procured from the above-mentioned companies and return them to be sent back to the suppliers."

ICMR had provided rapid antibody test kits to states with clear instructions that they are to be used only for surveillance purposes.

ICMR advocates that RT-PCR throat or nasal swab test is the best use for diagnosis of Covid 19. The test detects the virus early and is the best strategy to identify and isolate the individual

Earlier this month, ICMR had asked states to stop using rapid antibody test kits for Covid-19 diagnosis for two days until they are validated again.