The MTA would likely need to have its entire workforce cleaning and disinfecting trains, buses and stations around the clock to stop the deadly coronavirus from spreading, according to a public health expert.

But the transit agency’s plan to clean frequently used surfaces in stations once per day and trains and buses every 72 hours is likely the “best they can do” under the circumstances, said Anthony Santella, an associate professor of Public Health at Hofstra University.

“The transportation agency is not going to all of a sudden call every single one of its workers to work around the clock, 24/7. You probably need that to really clean things as much as they should be,” Santella told the Post, noting that multiple hands touch MTA surfaces every few seconds and that the virus often goes days undetected.

“Those resources simply do not exist. You would have to basically stop doing several other public health initiatives that are equally important to this,” he added. “What can they do without a lockdown or curfew or scaring people? Take precautions on things that could cause harm to New Yorkers.”

As of noon Tuesday, the MTA said transit workers had disinfected 420 subway stations, 1,905 subway cars, 1,974 buses, 300 Long Island Rail Road train cars, 60 percent of Metro-North’s rolling stock and 64 of its 124 stations, Chairman Pat Foye told reporters at a press conference in lower Manhattan.

Penn Station and Jamaica — key stops on the LIRR — were also cleaned Monday night, and cleaning is underway at the railroad’s remaining 120 stations, Foye said.

The agency is also transmitting a public service announcement across its properties advising riders to wash their hands and cover their mouths when they cough or sneeze.

“We’re transportation experts, not medical experts,” Foye told reporters. “We’re following the guidance of the CDC, the State Department of Health and public health professionals.”

Santella commended the agency for its messaging.

“There’s very [little] government can do beside putting out these messages and being upfront with the public,” he said.

The MTA’s new cleaning regimen comes as two coronavirus cases have been confirmed in the New York City region — a woman who recently traveled to Iran, but did not take public transit since returning, and a Westchester lawyer who commutes into the city.

The agency said it does not know if the second confirmed COVID-19 patient or his relatives had taken public transit since contracting the virus.