As Virginia works to preserve its own limited stockpile of tests for COVID-19, the disease caused by a strain of novel coronavirus, health officials are encouraging residents who don’t meet the state’s risk assessment to pursue testing through private labs.

The messaging comes less than a week after LabCorp and Quest Diagnostics, two of the nation’s largest networks of private laboratories, announced they were releasing their own novel coronavirus test for doctors and qualified health care providers. The move was framed by many hospitals and health officials as a way to expand testing for potential coronavirus patients who don’t meet the state’s narrow criteria for screening.

“Currently there are limited numbers of tests available, but we have more today than we did yesterday,” said Dr. Lilian Peake, Virginia’s state epidemiologist, at a news conference Wednesday. “[Virginia Department of Health], [Virginia Division of Consolidated Laboratory Services] other public health labs, and private labs are sharing information as we work through this and we are pursuing every opportunity to meet Virginia’s needs.”

But Peake and other health officials are also increasingly direct about the fact that Virginia has limited capability to test for COVID-19 at its own state lab, which still returns test results more quickly than private companies. Lab director Denise Toney estimated Virginia currently has the capacity to test between 500 and 600 patients. The state is expecting to receive two more test kits from the Centers for Disease Control and Prevention today or tomorrow, which each have the capacity to test about 100 people.

The CDC has sent fewer tests per kit than the state initially received from the agency. In a briefing with reporters on Tuesday, Toney said the most recent kit contained 500 reaction tests — half the number that were included in each of the first two orders.

Nine Virginia residents have now tested positive for novel coronavirus, including four who traveled internationally in Egypt on a Nile River cruise. The most recent patient to test positive was a teenager in the Hanover County area who returned from a country with community transmission of the virus, according to VDH.

At Thursday’s press conference, Gov. Ralph Northam urged Virginians to prepare for more positive results as the disease spreads across the region. In Washington, D.C., a reverend at Christ Church Georgetown potentially exposed hundreds to the virus. One of Virginia’s latest positive cases, a Loudoun County resident, is believed to have contracted novel coronavirus after attending services there.

Spread of the virus in Virginia would significantly strain the state’s current testing supply, even as the officials work to expand their resources. Other states have seen rapid increases in case numbers linked to a small number of patients. In New Rochelle, New York, more than 50 cases have been traced back to a single patient.

While Peake says Virginia has still seen no evidence of community spread — when transmission of the virus can’t be linked back to international travel or contact with another infected person — the state is limiting the number of people tested for the disease. Fewer than 70 patients have been tested statewide, according to the VDH website.

The department recently stopped reporting the number of residents being monitored for the disease, but older versions of the webpage show that 166 were currently under monitoring as of Monday, and 252 had completed monitoring without further public health action.

“Testing at the state lab is being prioritized for people who have respiratory symptoms and were in contact with a confirmed case, traveled to an area where the virus is widespread, or are in a nursing home,” Peake said Thursday.

In reality, that limits the state’s ability to track the disease, and has led to delay in screening for patients who didn’t meet those criteria.

A Virginia Beach couple who contracted COVID-19 after traveling in Egypt were initially discharged from a local hospital last Friday without being tested. At the time, the country wasn’t considered a high travel risk, but that’s quickly changed — at least regionally — as multiple cases in Maryland and Virginia have been linked to similar Nile River cruises.

At the federal level, though, Egypt still isn’t under a travel advisory for COVID-19. And the difference between CDC guidance and regional spread — combined with ongoing concerns over testing availability — means it’s still unclear to what extent private laboratories will expand access to the test.

In a statement from spokesman Dale Gauding, Sentara — the hospital system that initially discharged the Virginia Beach couple and later tested them at a different facility — said the state’s lab in Richmond was still the “primary testing site in Virginia.” Private laboratories offer “additional options for physicians and patients,” Gauding wrote, but individual doctors and hospitals still have to decide whether to request a test.

The companies also process their tests more slowly than the state lab, which can return results in less than a day, Toney said. LabCorp’s turnaround time is currently between three and four days, spokeswoman Pattie Kushner wrote in an email. That delay might not matter for a low-risk patient, but it’s significant for someone who was hospitalized for the disease, said Virginia Health Secretary Dr. Daniel Carey.

“To know that they didn’t have it would have an impact on the isolation precautions,” he said. “It’s really important because it affects the isolation and the intensity and the amount of protective equipment that we’re trying to conserve.”

LabCorp has the capability to perform several thousand tests per day, according to Kushner, but she didn’t provide additional information on how many samples the company has tested or whether it’s facing a backlog of requests. Testing is only available through clinicians or other health care providers, and is “for use with patients who meet current guidance for testing,” she wrote.

Most often, that guidance is set by the CDC, which has shifted its criteria for testing several times since the virus first appeared in the U.S. Doctors are now urged to use their clinical judgement when determining which patients should be screened.

Virginia Health Commissioner Norman Oliver said no patient would (or should) be tested without symptoms of the disease, including fever and difficulty breathing. Travel history and close contact with a diagnosed case are also clear reasons for screening, along with age and underlying conditions. But in an environment with limited testing, it’s more difficult for doctors to make tough calls on patients who might not check all the agency’s boxes, he said.

“If there were more tests available, I’m sure there would be more testing,” Oliver added. “And then you could more effectively implement the CDC’s guidelines, which is to do it on the basis of clinical judgement. Right now, it might be clinically advisable, but there are no tests available. And I think that hurts people.”

Both the University of Virginia and Virginia Commonwealth University are working to develop their own COVID-19 tests, but it’s not certain when they’ll be publicly available, the universities have said. CDC Director Robert Redfield recently expressed concern that nationwide efforts to develop more testing could be hampered by a shortage of critical lab materials.