What is antigen testing and why has it become an important tool for providers involved in treating COVID-19?
To begin with, there are two types of diagnostic COVID-19 tests used to determine whether or not someone has contracted the virus.
PCR testing is the most common test. It works to detect the virus’s genetic material and is used whether the patient is experiencing symptoms or not.
Antigen testing is the second option. It detects specific proteins from the virus. It is administered to patients who are experiencing symptoms.
Both types are used at Sanford Health. Both serve to help providers care for patients better.
“Our PCR testing is always going to be what I would call the ‘gold standard’ that we use for our ED patients and for our in-patients as long as we have reasonable turnaround time,” said Erica DeBoer, Sanford Health chief nursing officer. “Antigen testing can work in tandem with our PCR testing. It can be used for symptomatic patients who we think have COVID-19.”
Antigen testing uses nasal swab
How is antigen testing different from PCR testing?
An antigen test uses a nasal swab like the PCR version. However, it doesn’t go as deep into the sinus area. The specimen collected is placed on a test strip and goes into an analyzer. Generally, the results come back in 15 minutes.
Recently, Sanford Health began using the LumiraDx version of the antigen test. For several reasons, the system marks an advance over previous antigen testing options.
“The test is more specific and more sensitive than the antigen testing we’ve had available to us in the past,” DeBoer said. “Because of the accuracy of the tests, we can trust those results better. For those symptomatic patients we can have a faster turnaround.”
Both tests have been a vital part of managing treatment. In this case, efficiency and accuracy in diagnosing patients, whether they have COVID-19 or not, gives care givers much greater insight into the next steps. The quicker they can take those steps, the more effective treatment can be.
“The No. 1 reason for doing this is that it’s a rapid test,” said Rochelle Odenbrett, senior executive director of laboratories for Sanford Health. “We will be deploying the analyzers to all the sites across the system to do the rapid testing.”
One of the best available
In short, providers will not necessarily depend on PCR testing and its typically longer results wait times. As a rule, a big advantage in speeding things up is that analysis of samples can take place in the clinics where the tests are administered.
“If someone tests positive and we get that information quickly, we can get them isolated and educated right away,” Odenbrett said. “For our patients who would qualify, we can get them into an outpatient treatment plan and really assist in keeping patients out of our hospital.”
The goal, then, is faster detection and better treatment.
“The LumiraDx test is one of the best on the market,” Odenbrett said. “It is highly reliable. We are hoping we’re going to have less false positives and negatives than we’ve seen with a lot of other antigen tests that have been rolled out across the country. This has about a 98% sensitivity.”
Sanford Health will be making this antigen testing available in phases. It will be expanded through the month of January to locations throughout the Sanford footprint.
- COVID-19 FAQs: How will Sanford Health deliver vaccines?
- COVID-19 Q&A: Inside the test lab with Rochelle Odenbrett
- What to do when you think you need a COVID-19 test