As the coronavirus continues to spread throughout the world, including in Tennessee, Gov. Bill Lee declared a state of emergency on Thursday while making plans to shore up the state's medical resources in anticipation of a wave of new patients.

The governor's action comes one day after the World Health Organization said COVID-19 had become a global pandemic, President Donald Trump ordered a ban on air travel from Europe, sports leagues suspended seasons and schools throughout Tennessee said they'd shutter campuses.

Lee's decision to declare a state of emergency comes two days after he said he such a move wasn't yet necessary until Tennessee had seen "clusters of affected patients."

"We believe there clearly will be more cases," Lee said Thursday on the need for the emergency declaration, minutes before a flood of sporting events were canceled.

"This emergency declaration is an important next step in our efforts to treat and mitigate the impact of this disease," the governor said.

While praising the governor for his declaration, Democrats criticized Lee, saying more needs to be done.

As of 2 p.m. on Thursday, state officials said Tennessee had 18 detected cases of COVID-19.

With the emergency declaration, Tennessee will join an ever-growing number of states to take similar action. As of Wednesday, at least 28 had declared states of emergency, according to the National Governors Association.

The declaration will also give Tennessee access to additional federal funding to combat the coronavirus. Before Thursday's announcement, Tennessee was set to receive $10 million from the federal government to help with the state's response.

First case declared a week ago

Since Tennessee's first case of the coronavirus was announced last week, Lee and others stressed the state was prepared and drastic measures like closing schools and businesses were not necessary.

"As confirmed cases surfaced in other parts of the world, we in Tennessee prepared early," Lee said March 5. He noted Tennessee was one of the first states to begin testing for COVID-19.

At the time, state officials said they had an adequate number of tests available. Department of Health Commissioner Lisa Piercey said at the time "the overall risk to the general public remains low."

As of Thursday, Tennessee had completed 88 coronavirus tests at its state lab. Piercey said as of Thursday morning, the state had the capacity to test at least 500 people, in addition to resources available through private labs.

"We continue to remain confident in our ability and the measures that we're taking to prevent the spread of this infection," Lee said last week.

On Tuesday, the governor said he didn't see a reason for schools and workplaces, including state offices, to close.

"We don’t see a reason at this point (to close state offices) because the threat is significantly low to Tennesseans," he said.

But on Thursday, Lee said the emergency declaration was necessary in light of additional cases while giving the state access to more money.

Lee warned vulnerable populations to stay home and avoid large gatherings.

"We also know this is especially serious for our neighbors who are elderly," he said, imploring everyone in the state to take the issue seriously.

"While the risk to the general public remains low, the risk to vulnerable populations is very real," he said.

Although Lee didn't define that vulnerable population at the news conference, members of his administration pointed to the definition by the Centers for Disease Control and Prevention.

The agency's definition includes "older adults" and people with serious chronic medical conditions such as heart disease, lung disease and diabetes. According to the CDC, vulnerable adults are those 60 or older or people who have those underlying medical conditions.

Lee encouraged Tennesseans to avoid non-essential visits to nursing homes and hospitals.

Piercey said the emergency declaration could help pay for additional costs to provide access to telemedicine.

The governor's latest move caps off a week that began with officials saying they would not release county-level data of infected patients. The decision was later reversed after criticism from across the state, including from local officials.

But as of Thursday, the Department of Health has refrained from giving additional information, including the age and sex of those infected.

Tennessee lawmakers continue work

The emergency declaration comes as Tennessee colleges and universities, as well as K-12 schools throughout the state, have closed, fans have been banned from sporting events, and festivals, concerts and conferences have been canceled. Minutes after Lee's Thursday announcement, the SEC basketball tournament in Nashville was canceled.

The NBA, NHL and Major League Soccer all suspended their seasons. Major League Baseball delayed the start of its season by two weeks.

Piercey said such actions are part of an effort to "flatten the curve" of cases of the coronavirus.

"That deals with slowing the number of cases in order to reduce the strain on our hospitals, health care resources and allow our communities more time to prepare," she said.

Meanwhile, state lawmakers across the country have taken action to reduce public gatherings and Congress has halted public access through April 1. But Tennessee legislators continued pressing ahead Thursday with their business.

House and Senate lawmakers pressed forward with their agendas, welcoming the Tennessee Titans and debating everything from honoring Trump to making the Bible the official book of Tennessee. The House did not ultimately vote on the Bible bill.

On Wednesday, Rep. John Ray Clemmons, D-Nashville, called for legislative leadership to temporarily halt the session. The House and Senate speakers have shown no sign of a forthcoming change.

Lee said it was ultimately up to legislative leaders to decide how to proceed, noting his administration was ramping up efforts to introduce his final proposed budget for the year. Lawmakers are constitutionally required to pass a budget each year.

In a joint statement, Lt. Gov. Randy McNally, R-Oak Ridge, and House Speaker Cameron Sexton, R-Crossville, encouraged those who planned to come to the Capitol and lawmakers' offices to stay away while vowing to press ahead with the session.

Hospitals ramp up efforts to prepare

Wendy Long, head of the Tennessee Hospital Association, said the state's hospitals are ramping up their efforts to prepare for an expected surge in patients who will come as a result of COVID-19.

"We are concerned, regarding the potential, for supply, equipment and manpower shortages down the road," said Long, who noted such issues would depend on demand. "We'll be monitoring all those issues very closely."

Long said the state is looking at options ranging from telemedicine to providing Tennesseans with longer lasting prescriptions to avoid having them visit medical facilities.

"Also looking at issues like canceling elective surgeries in order to free up beds and really upping our efforts to discharge patients," she said.

House Majority Leader William Lamberth, R-Portland, remained confident Thursday the state's hospitals had an "enormous amount of capacity" and could treat anyone who needed it.

"It is going to continue to spread, we are ready for it, and we will make sure that anybody (who) needs treatment, gets that treatment," he said.

For all the latest efforts by the state, Democrats said more needs to be done.

"This is an emergency," said Senate Minority Leader Jeff Yarbro, D-Nashville. "Coronavirus represents a serious threat to Tennesseans, and it's time for the state government to act like it and to take decisive action."

Yarbro said Tennesseans need to hear about the plans every state agency and department has regarding the coronavirus.

"The effectiveness of the United States response to this disaster is ... going to be determined by how effective local and state governments are," he said, rejecting the notion that politics were at play while raising such questions himself. "It's not going to cut it to just follow the lead of the federal government."

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Reach Joel Ebert at jebert@tennessean.com or 615-772-1681 and on Twitter @joelebert29.

What to know

According to the Centers for Disease Control and Prevention, the risk of being exposed to the coronavirus (COVID-19) for most people is low. The CDC recommends taking simple, everyday steps to avoid catching or spreading respiratory diseases, including COVID-19. These include covering your cough or sneeze and thoroughly washing or sanitizing your hands. Call your doctor and stay home if you are sick. Get more information at CDC.gov/coronavirus or contact the Tennessee Department of Health coronavirus information line at 877-857-2945 from 10 a.m. to 10 p.m. CST daily.

As of 6 p.m. CST on Thursday, the total number of coronavirus cases are:

Tennessee: 18

Williamson County: 8

Davidson County: 6

Shelby County: 2

Knox County: 1

Sullivan County: 1

United States: 1,215

Worldwide: 125,288

Source: Tennessee Department of Health; Centers for Disease Control and Prevention; World Health Organization