Jan. 14, 2022 – As the Omicron genre has spread to the US, it is now said to be more than 98% of COVID-19 cases, the need for lab testing has increased dramatically – especially since home antigen tests are in short supply.
Over and over again, there are also complaints from testers, which repeat this troubling question:
How long does it take for the results?
The promised turnaround time of 24 to 48 hours is up to several days, as people wonder if they have isolated or continued with their regular schedule.
The increase in volume is a major factor, of course, but not the only reason.
“You may be surprised by the delay in time,” says Dan Milner, MD, chief medical officer at the American Society for Clinical Pathology, an organization of laboratory experts.
The nasal passage – from the collection site to the results tested by text or email – is more complex and difficult than most people think, Milner and other experts say. Many of the steps along the way, as well as other activities, including the emergence of COVID-19 among lab workers, could delay the timing of the change.
First, Volume Problem
Global statistics as well as daily statistics from individual labs reflect the increasing number of test requests.
Pa Jan. 11, the average COVID-19 test in the US arrived about 2 million a day, a 43% increase in 14 days.
As of January 12, Quest Diagnostics, a medical facility with more than 2,000 US locations, had tested the COVID 67.6 million tests since its inception in 2020. This was an increase of about 3 million since December 21, when all were present. 64.7 million.
At the UCLA Clinical Microbiology Lab, more than 2,000 COVID tests are performed daily, compared to 700 or 800 last month, says Omai B. Garner, PhD, director of Clinical Microbiology for UCLA Health System. And they do not think that the demands have been met.
In Tucson, AZ, at the Paradigm Site Services, which forms partnerships with local governments, businesses, and others to test, 4,000 tests a day take place, compared to every 1,000 days in early November, says Steven Kelly, CEO.
In addition to the volume, there are also some constraints that limit the transition time.
Swab Collection, Carrying, Driving
“People do not understand everything that is going on,” Garner said. One misconception is that the swab is inspected at the base of the pile. That’s usually not true – with PCR running (and expensive) trial pages sometimes less.
After collecting the nose, the sample is printed in a tube, which is then sent to the lab. It can be transported by courier to a nearby museum, or it can be sent away, especially if it has been collected in the countryside.
“Someone might be shaken and the swab should come out,” Garner said.
And even a swab that is transported by the senders to a local testing facility can take longer than expected, if traffic is heavy or the weather is inclement.
Along the way, temperature control is essential, Kelly of Paradigm says. “Samples should be stored at the appropriate temperature.” Carriers often keep the samples in the cold to transport them.
Arriving at the Lab
When the swab reaches the lab, samples should be inserted.
Next, the speed of the test depends on the number of tests received simultaneously – as well as the number of labs, taking into account staff and sample evaluation tools.
Working in a lab is another matter. As the need for testing increases, laboratories are struggling to increase staffing. Requirements vary according to the government, Garner says, but those who evaluate the tests should be laboratory scientists with training and expertise. And like other businesses, laboratories are working with employees who have COVID-19 and must resign in order to isolate themselves.
Labs staff also have to deal with a very serious problem, says Kelly. His company has also hired 30 more employees in the last 3 weeks, bringing in 160. Some work 7 days a week.
Test kits – or lack thereof – can also slow down the process.
Although Garner says he is often asked if false laboratories are coming out, he says he does not know anything. And it’s easy to look at lab information.
Accredited labs are certified under CLIA – Clinical Laboratory Improvement Amendments 1988. Under CLIA, federal standards apply to all US locations or testing centers for human testing to diagnose, prevent, or treat disease. The CDC has a CIA Laboratory Search Tool check the lab by name to see if it has a certificate.
Countries may also provide information on certificates and other tests. For example, California’s COVID-19 Testing Task Force publishes its own lab list, a detailed description of the location, the number of tests performed each week, and the duration of the adjustment.
Analysis on Lab
Labs test two types to detect COVID-19. The antigen test detects other proteins in the virus.
“Lab-made antigen tests are not very different” with a quick home test, Milner says. There is a control line and a test line that are used to detect the virus.
PCR (polymerase chain reaction) tests detect genetic predisposition.
“RNA is removed from the samples and refined by our device,” said Mariah Corbit, a results officer at Paradigm Laboratories.
Special chemicals and enzymes are added. PCR thermal cycler machines develop several methods of heating and cooling to analyze the sample. PCR technology allows scientists to develop small amounts of RNA from one sample to another DNA, which multiply until any virus is detected.
One of the chemicals emits fluorescent light if the virus is present in the sample. That signal is identified by a PCR machine.
PCR testing may also give an idea of the amount of virus a person has, says Chris Johnson, MD, chief medical officer of Paradigm Site Services.
Once the analysis starts, it is possible to estimate how long the results last, Milner says.
The most comprehensive analysis is PCR testing, which varies from lab to lab but usually takes about 1.5 to 2 hours, he says. Antigen analysis “takes about 20 minutes longer,” says Milner.
In the case of rapid PCR tests, which promise results in 1-2 hours or less but can cost up to $ 300, the repair time can be adjusted to get results faster, Milner says. And often, positive results are more immediate than negative ones. “If you read in real time, you can get good results in 20-30 minutes and say it.”
Areas that offer quick tests may be testing only COVID and may be testing on the same site, Milner says, allowing faster conversions. “If they are approved by the CIA, the type of test should be good,” he says.
The definition of a lab for the time to change the speed test may differ from that of a person expecting results. Quest Diagnostics, for example, states that its conversion time starts at end of day when the sample is collected and ends at end of day which results are reported.
Confirmation of Results
The good result is described as such, just as the bad. “There is no conclusive test,” says Garner. “This is why labs have to pass reliable tests.”
But the test is repeated if the initial results are not clear, Garner says. And if not conclusive again? “We release as uncertain,” and other tests may be called.
When completed, the results are sent via text or email.
Long-Term Answers
With no downsizing demands in the near future, long-term planning is needed.
“According to the lab, we are all frustrated because we do not have the equipment and the ability to meet demand,” says Garner. “In general, we did not develop experimental equipment to deal with the epidemic.”
At the beginning of the epidemic, he said, as demand grew, “we should have seen it as a necessary building block.”
At this point, lab operators are aware of the importance of timely results, but do not despair to ensure accuracy. “We want to make sure it goes well,” says Kelly.
