Everything old is new again when it comes to battling a novel coronavirus with no cure or vaccination.

Public health officials point to face masks, social distancing and good hand hygiene as pillars of the response to the coronavirus, along with robust testing and contact tracing. But there's one last-resort tool: the quarantine order.

Quarantines have been used to control disease among humans and animals for hundreds of years. The word derives from the Italian word for 40 days, quaranta giorni, because ships returning to port from far-off lands with infections would have to anchor for 40 days...