The new classification of districts was announced following a video conference chaired by the Cabinet Secretary on April 30 with the Chief Secretaries and Health secretaries of states.
"It is important to ensure that we identify pockets of critical interventions for a focused management of COVID -19 at the field level," Union Health Ministry Secretary Preeti Sudan said in a letter to the Chief Secretaries of all states and UTs.
She said the districts were earlier designated as hotspots/red-zones, orange zones and green zones primarily based on the cumulative cases reported and the doubling rate.
"Since recovery rates have gone up, the districts are now being designated across various zones duly broad-basing the criteria. This classification is multi-factorial and takes into consideration incidence of cases, doubling rate, extent of testing and surveillance feedback to classify the districts," Sudan said in her letter.
A district will be considered under green zone if there has been no confirmed cases of COVID-19 so far or there is no reported case since last 21 days in the district, according to the letter.