Updated Wednesday at 4:20 p.m. ET
After a slow initial roll-out, test kits for the new coronavirus are now becoming more widely available in the United States. That means a big surge in testing is coming — one that will likely cause a significant increase in identified cases of the COVID-19 illness.
Here are some things to know about the tests.
What is the current availability of coronavirus testing?
Vice President Mike Pence, who is leading the government's coronavirus response, said Wednesday that more than 2,500 kits are being distributed around the country this week. That will make more than 1 million tests available to hospitals that have requested them, particularly in regions where cases have already been identified, he said.
In testimony Tuesday, Sen. Patty Murray, D-Wash., was skeptical that the tests would soon be widely available.
Currently, the tests are available at state and university labs in each state, Pence said.
"Our objective is to make tests available broadly to the American public" by going to their doctor or local pharmacy, Pence said. The Centers for Disease Control and Prevention guidance on testing has changed so that "any American that wants to be tested for the coronavirus on their doctor's indications can be tested," he said.
Pence met with CEOs of commercial laboratories on Wednesday to discuss meeting the need for testing. Those labs, along with academic labs, have formed a consortium to share information and hasten the availability of tests to the broader American public.
Pence said that testing would be focused on the areas hit hardest so far by coronavirus cases.
If I think I might have the coronavirus, should I get tested?
The most common initial symptoms of COVID-19 are fever, a dry cough and shortness of breath. Call your doctor or your local health department if you believe you might have the virus, and you'll be advised of the best course of action.
It's important to remember that not everyone who gets infected gets sick and symptomatic. Also, it's flu season, so lots of people with flu-like symptoms have just that: the flu.
And to guard against becoming infected, start by practicing good hygiene: Wash your hands with soap and water frequently. Stay home from work or school if you're sick. It's possible you could get the virus and not know it because your symptoms are mild — so it's important not to pass the virus on to others who could be especially vulnerable to it.
How does the test work? Do you get tested at a hospital?
If a patient is suspected of having COVID-19, the person will most likely be tested at a hospital.
A medical professional will swab inside a patient's nostril and throat. If the patient has a wet cough, the health care worker will also collect sputum (the mixture of saliva and mucus that is coughed up). These samples will then be examined in a lab for genetic material that indicates whether the coronavirus is present.
So who decides who'll be tested?
Right now, it's up to state and local health departments to decide whom to test. The CDC provides clinical criteria to health care professionals for determining whether someone should be classified as a person under investigation for COVID-19.
That criteria was expanded on Wednesday to include a wider group of symptomatic patients. Its advice to health care professionals now says clinicians should "use their judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested."
The guidance goes on to say that who is tested depends in part on whether there are already cases locally or if the patient has had contact with someone who tested positive for coronavirus. It notes that most people with confirmed COVID-19 cases exhibit fever and/or symptoms of acute respiratory illness, like cough or difficulty breathing. Clinicians are strongly encouraged to test for other illnesses like flu.
Previously, some people had told NPR that they had asked to be tested for the virus because they were experiencing some flu-like symptoms, but they were not tested. In some well-publicized cases, people detailed their unsuccessful efforts to get tested. The Trump administration says it is working to make the tests broadly available.
Who pays for the coronavirus testing?
The Department of Health and Human Services has designated coronavirus testing as an "essential health benefit," Pence said Wednesday.
That designation ensures the test will be covered by health insurance plans, Medicare and Medicaid.
Will the test tell me if I had coronavirus but got better?
No. The test will show only whether you are currently infected with the virus. It will not show whether you had the virus in the past.
What does the test's wider availability mean for the U.S.?
As testing becomes more accessible, it's likely the tests will find infections around the country — including cases that have gone undetected for a while.
A genetic analysis of the virus in Washington state published Saturday found that the virus might have been circulating there for weeks and that hundreds of people might already be infected.
The test also means public health authorities should be able to catch new cases more quickly.
How many tests are available?
The CDC says it has enough kits to test at least 75,000 people, and more are on order.
Separately, Pence said 2,500 diagnostic test kits are being sent to labs, which he says will allow for over 1 million tests.
Each lab that orders a diagnostic panel from the CDC to test for COVID-19 will receive one diagnostic panel initially, and each panel can test 700 to 800 patient specimens.
Why hasn't broader testing been available until now?
The first test kits sent by the CDC to state and local labs didn't work as planned. It was a three-step process, and the third step was causing problems. The FDA subsequently authorized the use of just the first and second steps to provide a definitive diagnostic.
That set the U.S. back several weeks, and public health officials lost a crucial window to contain the virus and prevent it from getting a foothold in the United States.
Secondly, the CDC was using very strict criteria to determine who could be tested. That's what happened with the community spread case last month at UC Davis Medical Center in Sacramento, Calif.
The CDC later revised the criteria for testing to include people who are so sick that they need to be hospitalized but don't know how they might have been exposed. It has since expanded the criteria further.
NPR's Rob Stein and Richard Harris contributed to this report.