Have you heard of the Project Management Triangle? It basically says you want a project to be good, fast and cheap, but you can only have two of those things.
Dr. Dawn Nolt is medical director of infectious disease prevention at OHSU Doernbecher Children’s Hospital. She says when it comes to testing for COVID-19, you can maybe have 1.5.
Dr. Dawn Nolt is the medical director for infection prevention at OHSU Doernbecher Children's Hospital.
OHSU
“I think tests are pretty good in their accuracy, and the speed of getting the test results and the cost of the test can vary in different communities,” Nolt says. “But right now, I think the barriers are really supply chain, which fluctuates due to demand. And also, really, the demand can slow down testing speeds.”
Nolt says, “I think the goal of every American getting a good, fast and cheap test is...not for another six months, if not longer.”
She spoke with OPB’s Geoff Norcross.
Norcross: “So when someone gets tested, what is actually being measured?”
Nolt: “There are three types of tests that are looking for COVID-19 and the ones that your listeners are probably most familiar with is the PCR tests that look for genetic material from the virus from that swab that probably just came from your nose. And the PCR test is very sensitive to detect minute viral particles. But the main shortcoming is that it can’t tell if it’s measuring the entire complete whole virus or just looking at debris from an infection you may have had before.
“Other tests are maybe more indirect. They will look at the person’s blood for antibodies, or proteins that are made from your immune system while it’s fighting off an infection. The main shortcoming is that antibodies can take at least a week to show up in your blood. And so it’s not very helpful to tell someone if they actually have an infection right now.”
Norcross: “You mentioned that swab that goes in your nose, and we put out a call for questions on Twitter.”
Really curious if the throat-swab method is as accurate as the q-tip-piercing-your-brain-via-the-nasal-passage method.
— Meg DesCamp w/bonus Loaf (@MegDesCamp) August 5, 2020
“Does that method produce more accurate results than a throat swab? Or, you know, spitting in a cup or anything else that you could possibly put in a cup?”
Nolt: “Yes, your listener had a very evocative description there. There are studies that when someone has been infected with COVID-19 they were able to sample different parts of the respiratory tract from deep in the lungs up through the throat and into the back of the nose, that nasopharyngeal area. The most sensitive is to really get a specimen from deep in their lungs, either through a procedure that would get secretions from there or a really good cough. And then the second most sensitive is really that swab that goes into the nasopharynx.
“Right now, the technology for detecting virus from the throat or from spit is just not as sensitive. And so right now, the most common way to get testing is through nasopharyngeal swabs.”
Norcross: “Are there tests in development that might be more accurate or easier to administer?”
Nolt: “The PCR test right now is pretty accurate, so I don’t think that aspect needs to be improved a whole lot. The focus of testing is really to get that turnaround time to be faster and, as you said, to be less painful, more convenient to get a sample. So the idea of testing a throat swab or something simple as spitting into a cup would be very nice. And I think developments are proceeding along those lines.”
Norcross: “Flu season is going to be here before we know it, and so that throws a whole new consideration into the testing scheme that we have in America. Could it be possible to get tested for COVID and influenza at the same time?”
Nolt: “Yes. Right now, we’re fairly lucky, right? Because we’re in the summer season and really the only respiratory virus that we’re worried about is COVID. But as the respiratory season comes in, we’re thinking about flu and RSV and other respiratory infections. So it’s very important to test for multiple things on one swab. And so we do have that capability. We have what’s called multiplex panels. Right now, manufacturers are working on adding COVID-19 to those panels, and some of those panels are actually in front of the FDA now to be reviewed. I’m hoping that these multiplex panels, which include COVID, are available to us during respiratory season, optimistically by early 2021.”
Norcross: “Let’s talk about a vaccine, because there’s a lot of urgency to create one and have it be ready to administer to people, hopefully this year. Are the samples that are being collected in these tests helpful to researchers who are working on creating a vaccine right now?”
Nolt: “Oh yes, absolutely. Every vaccine that’s being tested is designed to include the PCR and antibody testings that we referred to before. When we are looking at people that participate in vaccine trials, we would like to make sure they don’t have evidence of the infection right now, so we would do a PCR test. And to make sure they have not had evidence of infection in the past, we would check for that antibody test. After they get the vaccine, those PCR and antibody tests would occur serially. And so that is very important during vaccine development.”
Norcross: “Have you been tested?”
Nolt: “Yes, I have.”
Norcross: “What was that like?”
Nolt: “Well, it was memorable. I felt ill. I was ill for a day and I recovered pretty quickly. But I went ahead and got tested because, as you know, I’m an infectious disease doctor. For me to bring COVID-19 into the hospital would be poor form and terribly tacky. So I got the NP swab experience and was analyzed by PCR, and it was uncomfortable. But it was worth it to have an answer personally and in the end to protect my family and my community.”
Norcross: “So for anybody right now who is thinking they would like to get tested, regardless of if they have symptoms or not, what’s your advice for them?”
Nolt: “I think that you should get a test only if it will influence your next actions. So if you’re feeling ill, absolutely you would get tested because that would influence whether or not you need to stay in quarantine, when you can go back to work or other areas of your life. You should not get tested if you’re otherwise feeling well, unless for some reason there is a medical indication or you were in contact with someone who was COVID-positive, and thus public health has asked you to be tested.”
To listen to the entire conversation, use the audio player at the top of this story.
