Why Your COVID Test Results Take That Long

Jan. 14, 2022 -- As the Omicron variant has swept crossed the U.S., present blamed for much than 98% of COVID-19 infections, the request for investigating astatine labs has skyrocketed -- particularly since location antigen tests are scarce.

On the rise, too, are complaints from trial takers, who echo this anxious question:

What's taking truthful agelong for results?

Promised turnaround times of 24 to 48 hours are stretching to respective days, arsenic radical wonderment if they should isolate oregon transportation connected with their regular schedule.

The accrued measurement is simply a large reason, of course, but not the lone one.

"You'd beryllium amazed by what the clip delays are," says Dan Milner, MD, main aesculapian serviceman for the American Society for Clinical Pathology, an enactment for laboratory professionals.

The travel of the nasal swab -- from the postulation constituent to the trial results arriving by substance oregon email -- is much progressive and analyzable than astir radical realize, Milner and different experts say. The galore steps on the way, arsenic good arsenic staffing and different issues, including outbreaks of COVID-19 among laboratory staff, tin hold the turnaround clip for results.

First, the Volume Issue

National statistic arsenic good arsenic regular tallies from idiosyncratic labs bespeak the roar successful trial requests.

On Jan. 11, the mean for COVID-19 tests successful the U.S. reached nearly 2 cardinal a day, an summation of 43% implicit a 14-day period.

By Jan. 12, Quest Diagnostics, a objective laboratory with much than 2,000 U.S. diligent locations, had logged 67.6 cardinal COVID tests since they launched the work successful 2020. That was an summation of astir 3 cardinal since Dec. 21, erstwhile their full was 64.7 million.

At the UCLA Clinical Microbiology Lab, much than 2,000 COVID tests are processed regular now, compared to 700 oregon 800 a period ago, says Omai B. Garner, PhD, manager of objective microbiology for the UCLA Health System. And helium does not deliberation request has peaked.

In Tucson, AZ, astatine Paradigm Site Services, which contracts with section governments, businesses, and others to supply testing, 4,000 tests a time are done, compared to a regular tally of 1,000 successful aboriginal November, says Steven Kelly, CEO.

Beyond volume, determination are different barriers that thwart the intended turnaround time.

Swab Collection, Pickup, Transport

"People misunderstand the full process," Garner says. One large misconception is that the swab is analyzed close astatine the constituent of collection. That's usually not existent -- with immoderate accelerated (and pricey) PCR trial sites sometimes the exception.

Once the nasal postulation is done, the specimen is sealed successful a tube, past sent to a lab. It mightiness beryllium taken by courier to a section adjacent lab, oregon it whitethorn beryllium shipped overmuch farther away, particularly if it’s collected successful a agrarian area.

"Someone could beryllium swabbed and the swab needs to spell retired of state," Garner says.

And adjacent a swab that's transported by courier to a section investigating laboratory could instrumentality longer than expected, if postulation is dense oregon the upwind turns bad.

En route, somesthesia power is important, Kelly of Paradigm says. "Samples person to beryllium stored astatine the close temperatures." Couriers often store the specimens successful coolers to transport them.

Arrival astatine the Lab

Once the swab arrives astatine the lab, the samples person to beryllium logged in.

Next, however rapidly it gets tested depends connected the measurement of tests received astatine the aforesaid clip -- and what the laboratory capableness is, taking into relationship unit and instrumentality to analyse the specimens.

Lab staffing is different factor. As the request for tests has increased, laboratories are having a hard clip adding capable staff. Requirements disagree from authorities to state, Garner says, but those analyzing the tests indispensable beryllium objective laboratory scientists with grooming and experience. And similar different businesses, laboratories are dealing with employees who declaration COVID-19 and indispensable permission enactment to isolate.

Potential laboratory employees indispensable besides header good successful a high-pressure situation, says Kelly. His institution has hired 30 much workers successful the past 3 weeks, bringing the full to 160. Some enactment 7 days a week.

Testing instrumentality -- oregon the deficiency of it -- tin besides dilatory down the process.

While Garner says he's often asked if fake investigating labs are popping up, helium says helium is not alert of any. And it's casual capable to cheque a lab's credentials.

Legitimate labs are certified nether CLIA -- the Clinical Laboratory Improvement Amendments of 1988. Under CLIA, national standards use to each U.S. facilities oregon sites that trial quality specimens to measure wellness oregon to diagnose, prevent, oregon dainty disease. The CDC has a CLIA Laboratory Search Tool to look up a laboratory by sanction to cheque its certification.

States whitethorn besides supply accusation connected certification and different investigating details. For instance, California's COVID-19 Testing Task Force publishes its lab list, detailing locations, fig of tests done weekly, and mean turnaround times.

Analysis astatine the Lab

Labs bash 2 types of tests to observe COVID-19. Antigen tests observe definite proteins successful the virus.

"Lab-based antigen tests are not that overmuch different" from the accelerated location tests, Milner says. There is simply a power enactment and a trial enactment utilized to observe the virus.

The PCR (polymerase concatenation reaction) tests observe familial worldly of the virus.

"RNA gets extracted from the illustration and is purified via our extraction instrument," says Mariah Corbit, compliance manager astatine Paradigm Laboratories.

Special chemicals and enzymes are added. A PCR instrumentality called a thermal cycler performs a bid of heating and cooling steps to analyse the specimen. The PCR exertion allows scientists to amplify tiny amounts of the RNA from the specimens into DNA, which replicates until immoderate microorganism contiguous is detected.

One of the chemicals produces a fluorescent airy if the microorganism is successful the sample. That awesome is detected by the PCR machine.

The PCR trial tin besides supply an thought of however overmuch microorganism the idiosyncratic has, says Chris Johnson, MD, aesculapian manager of Paradigm Site Services.

Once the investigation begins, it's imaginable to estimation however agelong results take, Milner says.

The longest investigation is for the PCR test, which varies from laboratory to laboratory but often requires astir 1.5 to 2 hours, helium says. The antigen trial investigation ''takes 20 minutes astatine the most,'' Milner says.

In the lawsuit of the accelerated PCR tests, which committedness results successful 1-2 hours oregon adjacent little but tin outgo $300, the processing clip whitethorn beryllium changed to get results faster, Milner says. And successful general, a affirmative effect shows up faster than a negative. "If you are speechmaking it successful existent time, you tin get a affirmative effect successful 20-30 minutes and study it out."

Facilities offering the accelerated tests whitethorn beryllium doing lone COVID investigating and whitethorn beryllium processing the tests astatine the aforesaid site, Milner says, allowing for the faster turnaround. "If they are CLIA-certified, the prime of that trial should beryllium OK,'' helium says.

A lab's explanation of turnaround clip for the non-rapid tests whitethorn disagree from that of the idiosyncratic awaiting the result. Quest Diagnostics, for instance, says its turnaround timeline starts astatine the end of the day connected which the specimen is collected and ends astatine the end of the day connected which results are reported.

Verifying Results

A affirmative effect is reported arsenic such, arsenic is simply a negative. "There is nary confirmation testing," Garner says. "This is wherefore labs request to tally reliable tests."

But the trial is repeated if the archetypal effect isn’t conclusive, Garner says. And if it's not conclusive a 2nd time? "We merchandise it arsenic indeterminate," and different trial tin beryllium ordered.

Once finalized, the results are sent via substance oregon email.

Long-Term Solutions

With nary slowdown successful request expected successful the adjacent future, semipermanent fixes are needed.

"From a laboratory standpoint, we are each truthful frustrated we don't person the infrastructure and capableness to conscionable the need," Garner says. "In general, we person not built the investigating infrastructure needed to combat the pandemic."

At the opening of the pandemic, helium says, erstwhile request archetypal ramped up, "we should person looked connected it arsenic a request to physique the infrastructure."

Meanwhile, laboratory directors cognize however important timely results are, but won't sacrifice velocity for accuracy. "We privation to marque definite it's done right," Kelly says.