SALT LAKE CITY (AP) — A growing number of health professionals around the world are filling an important role in the effort to guard against a resurgence of the coronavirus. In the United States, some experts say an estimated 300,000 contact tracers are needed to adequately curtail the spread. Contact tracing requires a hybrid job of interrogator, therapist and nurse as they coax nervous people to be honest. The investigators focus on finding out who COVID-positive people have been near. That helps determine who could be infected and need to be alerted. The tracers stay in touch with some of the contacts throughout the 14-day incubation period.