The Big Apple’s heavily touted coronavirus tracing program is having trouble tracking down sources of at least 80 percent of the COVID-19 infections in New York City, Mayor Bill de Blasio acknowledged Tuesday.

“People want firm, specific answers and, understandably, we would like for things to be clear and neat and that’s just not what the coronavirus usually gives us,” Hizzoner said during his daily briefing. “We just don’t have sites or activities that led to anywhere near the number of cases you would think.”

City health experts have said that roughly 10 percent of infections in the city can be traced back to travel outside of the area, while another 5 to 10 percent of cases can be linked back to individual sources and instances of infection.

But that leaves more than 80 percent of COVID-19 infections without a clear source, a startling new development that is complicating the city’s fight to stave off a second wave of the coronavirus pandemic that’s already sweeping across most other parts of the country.

“The challenge is how diffuse this is. And when it’s this diffuse it isn’t always as simple as, ‘oh, I went to a restaurant or I went to a gym’,” de Blasio added. “A lot of times there isn’t an obvious place because there’s a substantial amount of community spread.”

The city’s Test and Trace Corps employs more than 1,200 who are tasked with contacting and interviewing people who test positive for the dreadful disease in an effort to ascertain how they contracted it — and, just as importantly, who else they may have exposed.

City Hall’s effort to build the program from scratch after the pandemic exploded got off to a rocky start in the summertime.

Initially, just one-in-three New Yorkers provided contact information for people they may have exposed to the virus. And the program struggled to hire Yiddish speakers, a problem that exploded into view as the city’s tight-knit Orthodox communities were the center of a COVID outbreak in September.

Statistics published by the Test and Trace Corps show that of the nearly 93,000 New Yorkers contacted so far by the program, just 63 percent have completed their intake forms.