A Capitol Hill woman canceled her vacation because she couldn’t get timely proof she wasn’t infectious. A biologist from Charlottesville threw caution to the wind and visited his elderly parents anyway. A young D.C. man, exposed to a sick family member, has waited more than 10 days to find out if he is a coronavirus carrier.

The nationwide surge in coronavirus cases has throttled testing turnaround times not only in hot spots, but in places that haven’t seen a dramatic spike in infections recently — including the greater Washington area.

Private labs have been hamstrung by supply line shortages and overwhelming demand. Some labs have prioritized hospital patients or contracts with big employers, including the NBA, placing the general public at the back of a line that can grow longer by the day.

In D.C., Virginia and Maryland, some patients who have been told their tests would take a few days are waiting two weeks or longer to get results, erasing the chance to do meaningful contact tracing and leaving them in limbo.

“If you want people to seriously quarantine, you can’t wait that long,” said Aaron Cushing, the fisheries biologist who had wanted a negative test result before taking his daughter to see grandparents in Upstate New York. “I would have very happily stayed at home for three to five days. But you can’t ask people to stay at home and put life and work on hold for three or four weeks.”

When D.C. resident Lauren Phillips-Thoryn, 36, called Tuesday about test results from a nasal swab taken seven days earlier, a city worker said the backlog was so deep, the hotline would no longer give test results by phone.

“I’m just infuriated. The volume of how many people this affects is exponential,” said Phillips-Thoryn, an event planner who thought she had been exposed to the virus at a backyard gathering and is at high risk of developing complications if she falls ill. She ultimately tested negative.

City officials have said most people tested in the District receive results within seven business days, up from a three- to five-day wait earlier in the summer. Testing companies such as LabCorp, Quest Diagnostics and BioReference have also publicly acknowledged delays, generally about four to six days once they receive a sample.

But for dozens of people who contacted The Washington Post or complained to public officials, the waits are much longer  — far too long to inform decisions about travel, quarantine or who else may be at risk.

Fayth Jones, 33, stayed home in Woodbridge after developing coronavirus symptoms — fever, chills, headaches, exhaustion — in late June. She called three urgent-care clinics and found a week-long wait to get tested, never mind get results. After being swabbed on July 2, she waited two weeks to get results. She said she was afraid to visit her mom on her birthday, worried that her grandfather, in his 80s, might end up hospitalized if she did.

“I don’t know what to do besides stay away from people and wear my mask,” she said Thursday, hours before finding out she had tested negative.

“Sadly, I think my experience is just the system working as designed,” she said. “It’s just so fractured and broken that it doesn’t work for people like me, who don’t have access to a rapid test.”

Jon R. Cohen, executive chairman of New Jersey-based BioReference, said demand started ramping up several weeks ago, first among nursing homes, then hospitals resuming elective surgeries, then large employers seeking to test workers returning to newly reopened businesses.

Next came members of the general public, encouraged by health officials to seek a test for any reason.

A hospital Cohen contracts with in Florida, an epicenter of the country’s latest outbreak, had been sending 500 samples per day. Now it sends 2,000. His company’s network of labs — including one in Maryland — can hypothetically run as many as 70,000 tests daily from samples in 50 states. But in reality, supply chain and equipment troubles can unexpectedly cut that output by 20 percent or more.

The labs use four types of analyzers, which in turn can depend on as many as 17 different specialized components, from chemicals to enzymes to pipettes. A shortage of any can act as a choke point.

“We live every day waiting for our supplies to come in,” said Cohen, who has prioritized testing for hospital patients, nursing home residents and workers, and daily swabs of the roughly 1,000 players, coaches, staff and media quarantined in the NBA’s “bubble” in Orlando.

He called the nationwide demand for tests “insatiable.”

Parham Jaberi, chief deputy commissioner of the Virginia Department of Health, said the testing scarcity was “reminiscent of the early days” of the pandemic. The country would benefit, he said, from a coordinated federal effort to smooth out supply chain troubles.

“We’re increasing the potential to spread the virus,” said Jaberi, noting that asymptomatic people who seek tests and face long waits for results may not dutifully quarantine.

While the delays are more pronounced among private lab companies that do the bulk of testing in this country, public labs are not immune.

Earlier this month, Jaberi said, state workers retrieved samples from backlogged private labs contracted with the state and rerouted specimens to labs at the University of Virginia and Virginia Commonwealth University. A state task force is debating how to prioritize testing and whether to publicly issue guidance curtailing access to who gets a test.

“Are we getting to the point where testing is getting to be a scarce resource, and we need to make more explicit recommendations as a state?” Jaberi asked.

In Maryland, Clifford Mitchell, director of the Environmental Health Bureau, said testing results have taken as long as two weeks at private labs. State labs still have capacity to turn around tests in a day, but the labs are reserved for complex molecular analysis and treating outbreaks.

Mitchell agreed the prolonged delays mean “you’ve lost a critical advantage in being able to slow the spread of the disease.”

But he’s reluctant to suggest the government roll back the message that anyone who wants a test should seek one. Broad testing and contact tracing remain the best tools for controlling the pandemic, he said. Eventually, testing capacity will catch up.

“We want people who think they may be exposed to get tested,” he said. “And we want to test people who are worried about spreading it to other people.”

For some people, the delay lowered the odds they’d seek another test in the future.

“To me, it’s a disaster,” said Cecilia Rogers, 70, who lives on Capitol Hill and decided to get tested after joining a Black Lives Matter protest in early June. “There’s no point in being tested if you have to wait that long to get the results.”

The first time she sought a test, she waited in line for an hour before counting 66 people ahead of her in the 90-degree heat and giving up. The second time, on June 18, a worker pulled all senior citizens to the front of the line.

She didn’t find out she tested negative until 19 days later, on July 7, when she called the city health department to request her results. The official notification arrived at her house July 11.

Rogers has canceled plans to spend two weeks in Maine, which mandates a 14-day quarantine for visitors unless they have a negative coronavirus test taken no more than 72 hours before their arrival. “I didn’t see how I could possibly fulfill that requirement,” she said.

Katherine Anderson, a single mother in Silver Spring, had to wait three weeks before getting test results for herself and a new babysitter so the sitter could start work.

“Today was liberation day,” Anderson said last Monday, after both she and the sitter tested negative. “I might celebrate this day annually.”

Amanda Lowenberger, a stay-at-home mother in Arlington, sought a test as a precaution on July 2, after a tickling feeling in her lungs developed into a cough. She found out she was negative 11 days later.

And while she knew she was supposed to quarantine at home until the results arrived, by Day 6 she had appointments that were difficult to move. She started rationalizing that she probably wasn’t infected anyway.

“I’d ask myself, ‘Is this an ethical thing to do to leave my house?’ ” she said. “It’s very surprising that this far into the pandemic, we’ve still not got the basics down.”

Jack Hickman, who lives in the District, sought a test after learning that a family member had tested positive. He wanted to make sure he wasn’t an asymptomatic carrier who could pass it to his three roommates.

Last Monday, his 26th birthday, Hickman dialed into the city’s hotline for his coronavirus test results and was queued as caller number 246. Two and half hours later, he was told he’d have to keep waiting.

“It makes me wonder about: ‘If you want a test, get a test,’ ” Hickman said.

By Sunday, he’d been waiting 13 days.

Teddy Amenabar and Fenit Nirappil contributed to this report.