After a slow start, testing for COVID-19 has accelerated in recent weeks, with large commercial labs joining the effort, drive-up testing stations being constructed in some locations, and new types of tests being granted by the Food and Drug Administration under emergency regulations.
Even for those who can get tested (and there is still a significant testing gap in U.S. hotspots). The wait for results can be exasperatingly long – not just hours, but frequently days. Sen. Rand Paul (R-Kentucky) did not get his positive test results for six days. And is now being attacked for failing to self-quarantine during that period.
The turnaround time for results can range from hours to days or even weeks
It’s a Step-by-Step Procedure:
A sample is obtained from the patient’s nose or throat using a particular swab. This swab is place in a tube and transported to a laboratory. Some large hospitals have on-site molecular testing laboratories. However, Transfer the vast majority of samples to other labs for analysis. More on this to come.
This transit time is typically around 24 hours but could longer depend on the distance between hospital and processing lab.
Once the material arrives at the laboratory, it is processed, which entails the extraction of the virus’s RNA, the molecule that regulates genes.
The RNA extraction stage is a limiting element, according to Cathie Klapperich, vice chair of the biomedical engineering department at Boston University. Only the largest laboratories have automated methods for rapidly extracting RNA from a sample.
After the RNA has extracted, specialists must combine particular chemicals with each sample and run them through a machine for analysis. A polymerase chain reaction (PCR) technique that may detect whether a sample is positive or negative for COVID.
Kelly Wroblewski, director of infectious disease programs at the Association of Public Health Laboratories, stated that a typical PCR test takes six hours to conduct, beginning to end.
Expanding Capacity Is Not Enough:
Initially, only a few public health laboratories and the federal Centers for Disease Control processed COVID-19 testing. Problems with the initial CDC test kits also contributed to the delay.
Wroblewski stated that the CDC now has a better testing kit and that 94 public health labs across the country do COVID-19 testing.
However, these laboratories can’t perform every necessary task. In normal circumstances, their primary purpose is routine public health surveillance — spotting more common dangers such as measles outbreaks or tracking seasonal influenza — “but not to do diagnostic testing on the scale required for this response,” she said.
The FDA gave large commercial labs. Such as those operated by Quest Diagnostics and LabCorp, permission to begin testing late last month.
The FDA has stated that it will not prevent private labs and diagnostic companies currently certified to do complicated testing from designing their test kits. Among those doing so are labs at notable hospital systems, such as Advent Health, the Cleveland Clinic, and the University of Washington.
How long do test results for COVID-19 take?
Antibody tests and diagnostic tests comprise the two types of COVID-19 tests.
Antibody testing assists in identifying antibodies that indicate a prior infection with the novel coronavirus.
Antibodies are proteins produces the immune system produces in response to an effective immune response to the COVID-19-causing virus. Antibody testing cannot diagnose current COVID-19 infection.
Molecular testing and antigen tests are the two types of tests that can detect COVID-19 infection. In general, molecular testing takes longer but is more precise.
Molecular tests (PCR tests):
Molecular tests also known as NAATs and PCR. They identify the COVID-19 virus’s DNA to determine if you are currently infect.
If performed within five days of the commencement of symptoms. They properly identify a positive test more than 90 percent of the time, according to a study from 2020.
Regarded as the “gold standard” of testing, and many nations now mandate a PCR test within 48 to 72 hours before arrival.
However, the test’s ability to detect the presence of the new coronavirus rapidly declines to approximately 70–71 percent between days 9 and 11. By day 21, it has decreased to approximately 30%.
Your physician will normally collect a nasal and throat swab during a PCR test. The sample is subsequently deliver to a laboratory for analysis.
Clinics that can process your findings on-site may be able to deliver them within hours.
Clinics that must send away results or have a backlog of tests may take a week or longer to provide your test results.
Rapid PCR tests are now accessible, but their accuracy raises some concerns among medical professionals. These tests can be conduct at home and do not need to be forward to a laboratory.
Antigen Tests (Serological Tests):
Antigen assays, also known as serological testing, seek to identify specific proteins on the virus’s surface.
Compared to PCR tests, they carry a greater possibility of a false-negative result, indicating that you may contain the virus in your body even though the test indicates otherwise.
If the virus is present in low quantities, your test will most likely indicate a false negative.
Antigen test also known as quick tests because some clinics can provide you with findings within minutes.
Since December 2020 Reliable Source, the Food and Drug Administration has authorized antigen tests for home use that offer results in less than thirty minutes.
Antibody Analyses (PCR Tests):
Antibody tests seek to identify a prior illness. According to the Centers for Disease Control and Prevention, it takes 1 to 3 weeks after infection starts for the body to produce antibodies. Therefore, they cannot be use to identify a present infection (CDC).
The test is often performed by pricking a finger and collecting a drop of blood. Some clinics may be able to provide same-day results, while others may require several days.