Nearly 1 million New York City residents probably have been exposed to the coronavirus, well above the number of confirmed cases, the city's top health official said Thursday. Data compiled by Johns Hopkins University showed that more than 147,000 people in New York City have tested positive for Covid-19 as of Thursday. "That really I think is the tip of iceberg for a number of different reasons," Health Commissioner Dr. Oxiris Barbot said at a news briefing. "New Yorkers have been heeding our advice that if they have mild symptoms, at this point in time, when you've got community-wide transmission, having a test result isn't going to change what we're going to tell you to do." New York City is still struggling to ramp up its capacity to test broadly for Covid-19, which means increasing laboratory capacity and acquiring necessary supplies such as test kits, swabs and reagents, which are chemicals needed to process the tests, Mayor Bill de Blasio said. Barbot added that the city still has to prioritize who gets tested. "We want to reserve testing for those individuals who are really sick enough to be in the hospital," she said. "With that being said, it wouldn't surprise me if at this point in time, we have probably close to a million New Yorkers who have been exposed to Covid-19." Widespread testing and tracing of people who come into contact with infected individuals will be crucial to easing restrictions and reopening the city, de Blasio said. He previously announced that the city will begin manufacturing its own test kits, hoping to ramp up as many as 50,000 per week in addition to those kits the city acquires externally. "We need the firepower of testing and tracing," he said Thursday. "The more testing we get the more truth we will find. The more testing we get, the more we can fight back and contain this disease. All roads lead to testing."

Antibody results

Later Thursday, New York Gov. Andrew Cuomo released the preliminary results of a statewide coronavirus antibody study, which estimated 13.9% of the New Yorkers have likely had Covid-19 already. The state randomly tested 3,000 people at grocery stores and shopping locations across 19 counties in 40 localities to see if they had the antibodies to fight the coronavirus, indicating they have had the virus and recovered from it, Cuomo said. The results differed across the state with the largest concentration of positive antibody tests found in New York City at 21.2%. He added the caveat that "these are people who were out and about shopping," so they may not have been strictly social distancing. "What we found so far is that the statewide number is 13.9% tested positive for having the antibodies," Cuomo said. "They were infected three weeks ago, four weeks ago, five weeks ago, six weeks ago, but they had the virus, they developed the antibodies and they are now recovered." On Wednesday, Cuomo announced that billionaire philanthropist and former NYC Mayor Mike Bloomberg will help the state develop and implement an aggressive program to test people and trace their contacts. Bloomberg will contribute $10 million and help to build an online program to train what Cuomo described as an "army" of tracers.

Risk of 'Backfire'

Lifting restrictions without enough testing and tracing infrastructure could lead to a "backfire" in which the virus resurges and health officials are unable to contain it before it spreads across the city again, de Blasio said. "Unless we are very careful and we have some good luck and some blessings thrown in, we have to be weary of a resurgence," he said. "It will not only backfire. It will set us back by months and months." Several states have announced plans to at least partially lift social distancing restrictions. Georgia Gov. Brian Kemp, a Republican, announced Monday that the state will reopen businesses on Friday, starting with retail locations such as gyms, barber shops, fitness centers and bowling alleys. Kemp's decision came after several states mostly in the South unveiled plans to restart parts of their economy. President Donald Trump said Wednesday he "totally disagrees" with Kemp's decision. Trump added that Kemp's decision violates the phase 1 guidelines the White House announced last week that recommends states wait to ease social distancing restrictions until there's widespread testing and a low level of community transmission.

'Hopes and prays'