YORK — Many people in Maine are having to wait as long as two weeks for COVID-19 test results as a surge in demand from southern and southwestern states has overwhelmed major national test processing companies.

Quest Diagnostics of New Jersey and LabCorp of North Carolina – behemoths of medical test processing – have reported being swamped by the demand as the disease has surged in those parts of the country. On Monday, Quest said its average turnaround time is seven or more days, with “a small subset” experiencing wait times of as long as two weeks, though certain priority patients were getting more timely results. LabCorp on July 8 said it had turnaround times of four to six days, up from one to two days previously, but hasn’t provided an update since.

Maine health care providers that rely on these national labs are feeling the effects.

InterMed, a large primary care provider in southern Maine that uses Quest, is experiencing 12-day delays in getting results, spokesman John Lamb said.

Maine Urgent Care, which provides testing at sites in Topsham, Lewiston and Augusta via Quest, has four-to-seven-day turnarounds for non-symptomatic patients, said Kate Carlisle, spokesperson for its parent entity, Central Maine Health Care.

CVS, which provides testing at its Auburn, Augusta, Biddeford, Portland and South Portland stores, also uses national labs and is experiencing delays of six to 10 days and sometimes longer, said Tara Burke, the chain’s New York-based spokesperson.

While it’s unclear what percentage of COVID-19 tests in Maine are sent to national labs, such long delays make the tests far less valuable. By the time a patient gets a result, they are likely to have passed the time when the disease is most contagious and the 14-day quarantine period they may have been trying to avoid may have nearly elapsed.

“Testing delays of a week or more are almost functionally useless in that they come too late to inform action,” Dr. Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, said via email. “If we learn late in people’s course of illness that they are infected, it means we’ve missed precious time to isolate them and stop them from spreading their infection to others.”

Fortunately most of Maine’s COVID-19 testing capacity is insulated from the crisis at the national labs, though increased demand from the summer tourist season has increased turnaround times.

The state’s largest hospital networks, MaineHealth and Northern Light Health, have in-house capacity to process tests from their patients and report no significant delays in securing results. Mount Desert Island Hospital and MaineGeneral in Augusta have partnerships with the Jackson Laboratory, whose processing site in Connecticut is unaffected. MaineGeneral spokesperson Joy McKenna said Wednesday it has a 24-hour turnaround time.

The Maine Center for Disease Control and Prevention’s own lab partnered with Westbrook-based veterinary medical provider Idexx in June to expand its in-house testing capacity, which processes tests collected from 22 “swab and send” sites across Maine. At Tuesday’s news briefing, agency director Dr. Nirav Shah said the turnaround time at the lab was about 36 hours from when it receives a sample, but that it can take a day for a sample to reach the lab and additional hours for a provider to convey the results to the patient.

Shah cited the delays at the national commercial labs as further evidence of the importance of Maine having set up its own lab capacity and specimen collection sites. While the prevalence of the disease in Maine remains among the lowest in the nation, national labs are exposed to the surging test demands that stem from the disease’s dramatic increase in Florida, Arizona and the Gulf States. Louisiana’s infection rate Thursday stood at 2,189 per 100,000 residents, or nearly eight times that of Maine, which has the third lowest rate in the country after Hawaii and Vermont, according to a widely followed tracker at The New York Times.

Jackie Farwell, spokeswoman for Department of Health and Human Services, which the Maine CDC is part of, said the underlying problem is the Trump administration’s failure to create a national testing strategy, but that Maine’s decision to build local capacity was proving critically important.

Maine CDC spokesman Robert Long did not respond to questions about how the delays might affect the state’s overall pandemic response.

The slowdown at the national labs has put further pressure on other testing providers just as the state hosts the annual influx of summer tourists, many of whom are required to show a negative COVID-19 test result in order to avoid a mandatory 14-day quarantine.

Dr. Jabbar Fazeli, a southern Maine geriatrician and vice president of the Maine Medical Directors Association, which represents nursing home medical directors, said he was involved recently in trying to get a nonresident with mild COVID-19 symptoms a test in the midcoast area. Some providers declined because they test only established patients, others because they test only people with more serious symptoms, and the rest because the person wasn’t a Maine resident, he said.

“It makes me nervous because the quarantine is on paper only and nobody comes to Maine to sit in their hotel for 14 days,” Fazeli told the Press Herald. “If you can’t get a test even when you ask for it, that might explain why there are so few cases.”

Very few non-residents have tested positive for the disease in Maine, according to the most recent data disclosed by the Maine CDC. As of July 18, a total of 133 such cases had been reported, with new cases increasing by a rate of 0.7 per day over the course of July.  Between July 1 and 18, nonresidents accounted for 6.4 percent of the COVID-19 positive tests in Maine.

In York, where day-trippers and cottage renters crowded the beaches last weekend, the most popular rapid test site has been overwhelmed by demand.

In partnership with the state, York Hospital established a drive-through testing site July 1 at its urgent care center on Route 1 that offered results in 20 minutes. It immediately became popular with tourists from Massachusetts and other states who, under the governor’s executive order, must show a negative test when checking into a hotel to avoid the quarantine.

With three Abbott Laboratories machines, York could process nine tests an hour, and anyone can sign up for a slot online by paying a $25 fee with a credit card. Although the site is open eight to 10 hours a day, the next openings are currently two weeks out.

“Word got out,” says Erich Fogg, York’s director of testing, who says 68 percent of the 1,600 tests they’ve run were for nonresidents. “People were attracted to a test you could get in 20 minutes and then get on with your vacation.” (Only 11 of the tests have come back positive to date.)

This is an economic, not just a public health, problem, argues Steve Hewins, president and CEO of Hospitality Maine, which represents the state’s hotels and restaurants.

Residents of Massachusetts and 45 other states are required to sign a form attesting to having had a negative test within 72 hours of arrival but have no effective means of doing so. “Test delays of up to 10 days in Massachusetts and many other states make this impractical and inconvenient for tourists to comply,” Hewins said. “The reality is that it takes about a week at most sites in Maine and even the few sites that use the state lab in Augusta, tests generally take at least 48 hours” to get back to the patient.

With an average hotel stay of 3.5 days in normal times, most people’s vacation would be over long before their quarantine period ended, he added, leading to massive cancellations of reservations in the Midcoast and Downeast Maine, which lie beyond day-trip range of Boston.

“While Massachusetts day-trippers, completely COVID-19 untested, freely travel the southern parts of Maine, the streets in Bar Harbor are largely deserted,” he added.

Farwell, the DHHS spokesperson, said residents of states such as Massachusetts that have a higher prevalence of the disease than Maine could get tested under the department’s standing order, regardless of whether they exhibit symptoms.

“Testing is available to them at the sites that test under the standing order, of which a subset are the swab and send sites,” she said via email. “There are a number of testing sites where results are available significantly faster than 7 to 12 days. Individuals are encouraged to call ahead to testing sites to inquire about the wait time for results and to address other questions.”