The Union Health Secretary Rajesh Bhushan has written a letter to the officials of five states including Kerala, Karnataka, Maharashtra, Telangana, and Tamil Nadu to closely monitor emerging clusters of Covid-19 cases and maintain an adequate number of tests, and send samples from infected individuals for genome sequencing.

"There are few states which are reporting a higher contribution to India's cases indicating the possibility of a localised spread of infection. There is, therefore, a need to follow a risk assessment based approach on the public health responses without losing the gains made so far in the fight against the pandemic," read the letter.