New Delhi, Nov 25 (IANS): The Centre on Thursday told all the states and Union Territories to be cautious about international passengers travelling from or through Botswana, South Africa and Hong Kong in view of a new Covid variant detected in South Africa.

In a letter to the states, Health Secretary Rajesh Bhushan said, "It has now been reported by NCDC that multiple cases of a Covid-19 variant -- 8.1.1529 -- have been reported in Botswana (three), South Africa (six) and Hong Kong (one). This variant is reported to have a significantly high number of mutations, and thus has serious public health implications for the country in view of the recently relaxed visa restrictions and opening up of international travel.

"It is imperative that all international travellers travelling from and transiting through these countries and also including all other 'at risk' countries are subjected to rigorous screening and testing. The contacts of these international travellers must also be closely tracked and tested."

The letter has directed the states to ensure that samples of travellers turning positive are sent to the designated IGSLs promptly as per the INSACOG guidance document issued by the Health Ministry.

The ministry has also told the states and UTs to adhere to the overarching 'Test-Track-Treat-Vaccinate' principle to ensure stringent implementation of containment measures as per ministry guidelines.