NEW DELHI: Government’s cluster containment strategy to tackle covid-19 has yielded good results, and curbing the spread of the infection will become difficult if lockdown measures for social distancing are not followed, the Centre said on Tuesday. “The government is adopting a strategy for cluster containment, which is producing positive results, especially in Agra, Gautam Buddh Nagar, Pathanamthitta, Bhilwara and East Delhi," said Lav Agarwal, joint secretary, ministry of health and family welfare. "While 326 persons have been discharged after recovering from the infection, India has a total 4,421 confirmed covid-19 cases.