Contact Tracing is the Key to Reopening America - But how does it actually work?

Contact tracing is key to reopening America. But how does it actually work? 

(Wednesday, April 29)
States across the country are laying the groundwork to launch massive contact tracing efforts 

to identify people who may have contracted the new coronavirus. Some public health experts 

say the efforts are crucial to relaxing social distancing measures intended to curb America's 

Covid-19 epidemic. But how does it work?  Read on ...