“It will have implications for authorities carrying out contact tracing of those potentially infected by contagious individuals, and could lead to many more people being required to go into quarantine. Under the old definition, ‘close contact’ was defined as being within 6ft of an infected person over a solid block of 15 minutes or more. That has now been amended to cover a cumulative 15 minutes or more over a 24-hour period.” CDC rewrites definition for coronavirus ‘close contact.’