WASHINGTON — Capitol Hill will stay wide open amid the deadly coronavirus health crisis — panicking members of Congress and staff who say the building is unprepared for an outbreak.

As the White House tightens visitor rules to protect President Donald Trump from COVID-19, The Capitol and its office buildings remain a free for all to visitors from across the country who may have come into contact with the virus.

“If members of Congress start falling ill with the disease, it won’t exactly bolster the nation’s confidence in our prevention efforts or leadership abilities,” one senior Republican staffer told The Post.

The Capitol rumor mill went into overdrive on Thursday afternoon when a congressional staffer went home sick, according to two sources — sparking unsubstantiated panic that they might have contracted the virus which has killed 14 Americans.

Especially concerning is the fact that many lawmakers aged in their 70s and 80s are in the highest risk group.

Dianne Feinstein (D-Calif.) is the oldest sitting senator at 86, while House Speaker Nancy Pelosi and House Majority Leader Steny Hoyer are both 79.

Handshakes are on the outs — with a panicked Sen. Debbie Stabenow (D-Mich.) seen dodging a handshake from a constituent and awkwardly bumping elbows with him instead.

So far, the only measure being taken in the building is the installation of extra hand sanitizer stations.

Florida Rep. Matt Gaetz wore a gas mask on the House floor on Wednesday to illustrate how unprepared the building is for an outbreak — calling members of Congress “human petri dishes.”

“Members of Congress are always in airports, taking selfies with other people’s phones,” Gaetz said. “If there’s anybody that’s going to get coronavirus it’s going to be the United States Congress.”

“House rules do not explicitly allow medical headgear even at this time of heightened concern. This is a rule that should be revisited.”

Florida Sen. Marco Rubio also said he believed an outbreak on Capitol Hill was inevitable.

“No one wants to talk about it, but it’s just practical: We have visitors coming here from all over the world and all over the country, all of us travel, staff travel, a lot of close contact, people in and out all the time,” he told the Wall Street Journal.

Congressional leaders this week met with the Sergeant at Arms, Capitol Police and the Capitol physician to talk about preparing for a potential outbreak, but the public galleries remain open.

A spokesman for the Office of the Sergeant at Arms told The Post they were monitoring the situation and would take any necessary steps “based on the guidance provided by federal, state and local health authorities.”

Up to 5 million people from around the world visit the Capitol each year. Members of Congress will also spend the weekend in their constituencies around the country before returning from the break on Monday.

There are now more than 250 cases of the virus in the US, while a 15th death was confirmed on Friday morning. The virus has killed 3,000 people globally and infected more than 100,000.

Nobody has tested positive for the virus in Washington, D.C., but three cases were confirmed in Maryland on Thursday — sparking fears it is only a matter of time before the health crisis reaches the nation’s capital.

Many staffers and lawmakers remain in the dark, with the Office of Personnel Management earlier this week floating the idea of people working remotely but failing to follow up.

Speaker Nancy Pelosi on Thursday said there were no plans to close the Capitol, saying it was impractical to ask lawmakers to work remotely.

“We can’t vote from home,” she said.

The idea isn’t exactly sitting well with people who work in Washington.

“There hasn’t been a great deal of information provided to Hill staffers yet on how we plan to address coronavirus or if we should proceed with normal office operations,” the senior staffer said, adding they don’t even know where the information would come from.

“The nation needs to know its leaders are well-equipped to address the threat coronavirus or any wide-spread health concern poses to the business of the nation.”