Alexi Rosenfeld/Getty Images New York City is set to hire 1,000 contact tracers in May, disease detectives who'll be tasked with tracking down the city's coronavirus infections, and warning people when they might've been exposed to COVID-19. City councilman Mark Levine told Business Insider that such a system is essential to reopening the city, "because otherwise you can't really have confidence that people you see around you in public aren't contagious." Visit Business Insider's homepage for more stories.