New Delhi, April 10 -- State governments have begun experimenting with the idea of containment zones to deal with the coronavirus disease (Covid-19). The mechanism is straightforward. Those clusters that have seen a rise in cases - and have shown traces of rapid transmission - are sealed. This can be in the form of a housing society, a neighbourhood, or even a district. Not only is the lockdown in the identified cluster enforced more strictly, there is also a complete ban on the movement of residents. Even essential supplies are delivered at home. Movement into these zones is limited to a small set of officials and health care workers. There is also aggressive screening and enhanced testing in these clusters....