WHYY By Joseph Ortiz, a contact tracer with New York City's Health + Hospitals battling the coronavirus pandemic, uses his tablet to gather information as he heads to a potential patient's home Thursday, Aug. 6, 2020, in New York. The city has hired more than 3,000 tracers and the city says it's now meeting its goal of reaching about 90% of all newly diagnosed people and completing interviews with 75%. (AP Photo/John Minchillo) A few weeks ago, a friend of Jill Fredel’s got an alert on her phone through the COVID Alert DE app, saying that she had been close to someone who tested positive for COVID-19.