This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

NEW YORK CITY — Staff at 16 New York City schools have tested positive for coronavirus, according to the union representing teachers.

Teachers returned to classrooms Tuesday this week to prepare for students. Classes are set to resume Sept. 21.

Two coronavirus cases had been confirmed Wednesday. Thursday’s positives occurred in one staffer at each of the 16 schools. The city’s test and trace program is being put to the test to see who will need to quarantine after the positive tests.

“School staff have access to free, expedited testing and we’ve encouraged all staff to get tested before they return to buildings while we continue to navigate the realities of a pandemic,” a spokeswoman for the Department of Education said Wednesday. “Our protocol is to immediately notify staff and Test and Trace will begin an investigation to determine any close contacts.”

New York City’s reopening protocols do not require schools to shut down when a single case is identified. Staff and students from that class will transition to remote learning.

Mayor Bill de Blasio said Thursday that there is no real plan to disclose positive tests because students are not back in school yet.

“Of course there will be days where you find a case in a classroom and classroom will have to be shut down, sometimes a school will have to be shut down,” he said. “But it’s a temporary reality.”

UFT President Michael Mulgrew says the city needs to be serious about their plan to protect students and teachers.

“We made sure we had an agreement on the most aggressive plan with the greatest safeguards because we knew the challenge we were facing. And if they can’t follow it then we know we’re going to have to fight about not opening.”

So far 15,000 staffers at the Department of Education have been tested for the coronavirus with 16 results coming back positive.

Mulgrew says the number of cases is not alarming, but the results are supposed to be back with 48 hours. He says these teachers were tested last week.

“We’ve worked to make testing as fast and convenient for school-based staff across the city and the results have paid off, with over 95% of tests coming back within 48 hours,” said Avery Cohen, a spokesperson for Mayor de Blasio. “We’re committed to testing every last case of the virus, and will continue to work in lockstep with UFT to ensure we are doing everything in our power to make schools safe. Our students and teachers deserve nothing less.”

Gov. Andrew Cuomo assured parents Thursday that they will be kept in the loop on their children’s school.

“The labs doing tests have to report to the state health department,” Cuomo said. “The school districts have to report, the school has to report. We did that by executive order so we will have the information.”