SARATOGA SPRINGS – They are two different things. The first, which can be done via a nasal swab, tests whether a person is infected with COVID-19. The second, which uses a drawing of blood, indicates whether a person may previously had been infected with the virus and built-up antibodies to potentially provide virus immunity, at least for the time being.
In the first instance, more than 50,000 people in Saratoga County have been tested for the COVID-19 virus, according to the state Department of Health, with about 750 of those people – a rate of approximately 1.6 % – having tested positive.
In the second scenario, examining for antibodies, local tests indicate about 9% of those tested had previously been infected with COVID-19 – although it would be misleading to subsequently assume that 9% of the overall local population has previously had the disease. “Probably in our community, it’s going to be a couple of percent,” says David Mastrianni, MD Senior Vice President, at the Saratoga Hospital Medical Group. “I don’t think it’s going to be very high, a few percent of people. Whether it’s 2, 3, or 4 percent I don’t know, but it will probably be in that range,” he says. “It’s going to be low so the point is we’ve done a really good job here (in Saratoga) of shutting down Covid. The bad news is that we‘ve got to keep doing a really good job because we have a lot of people who are not immune.”
Mastrianni says the initial tests that look for the virus have taught that some people who get infected may not have any symptoms at all for a couple of days. “You could be asymptomatic and that’s one of the tricky parts about it. There are probably people out there who have some of the virus,” he explains. When people do get symptoms, they can range erratically from person to person. The virus typically will stay in the body for about 10 days, and one of the ways the body’s immune system fights it off is by producing antibodies.
Antibodies
“Antibodies will typically start to turn up after 10 days or so. They persist for some months – we don’t know exactly how long, but for quite a number of months,” Mastrianni says. While not known exactly how long the antibodies persist, it is believed they provide a temporary immunity period. “We think for most people those antibodies do protect them. How long that protection is good remains a mystery, but at least for some months.”
There are exceptions – people who make incomplete antibodies, or whose immune system doesn’t work quite right for example, but antibodies creating immunity is an important factor, and the length of time that immunity exists is also key in learning how often a person would need to be vaccinated, if and when a vaccine is introduced.
“For right now what we’ve seen is that the vast majority of people who go through the illness get the antibodies and they don’t get (the virus) again,” he says.
“Overall, we’ve seen about 9% positive, but most of those people (tested locally) had the illness, we knew that. They got really sick and had a positive swab test. Then, some other people from the
community came who had talked to their doctor and thought: Gee, I had a flu-like illness in March or April and maybe I had it. So, they wanted to know. And so we’ve ended up at about this 9% positive rate -but that’s really dependent on who came in to get the test, so I’m not sure really what to make of that percentage.” The number of antibody tests locally conducted is “in the hundreds.”
His practical advice: if one was previously sick and it’s important to them to know whether they had COVID, they should talk to their doctor about getting the antibody testing done. The antibody tests are reliable, but not perfect, he adds. “I would be nervous about doing it if you had no real reason, because you might get a false positive, and that would be bad for you to think you were
protected when you weren’t.”
Pooled Testing
Earlier this year, as the need for COVID-19 testing began to increase, Saratoga Hospital started pooled testing for the virus, essentially batching multiple patient tests together to conserve test cartridges. To date more than 2,150 test cartridges have been preserved, enabling the hospital to test all patients before they’re admitted and isolate those with the novel coronavirus.
Pooled testing combines samples from several low-risk people in a single vial. If the test is negative, everyone whose sample was combined has tested negative for COVID-19—using supplies for only a single test. If the test is positive, each person must be retested individually.
“We wanted to test everybody but we didn’t have enough cartridges, so we started batching them, and we proved that it worked,” says Mastrianni, who co-authored an article about the results of Saratoga Hospital’s pilot program, published this month in the Journal of Hospital Medicine.
“We started with 3 (people) and now we’re doing between 3 and 5, depending on what our need is. It’s been a very successful way of taking people who got admitted to the hospital and
trying to tell best we can whether they had Covid.”
Where We Are Now
“I think this region had done a great job. We’re low, but I think it’s a critical point over the next month. If we can get everybody to wear masks and be careful and avoid the big groups or travel to the hotspots, I think we can stay somewhat open and do a lot of things that we want to do in our lives,” Mastrianni says. “But, I think if we let this back in it’s going to be miserable.
“Everybody is asking: What’s going to happen when school opens? Well, if your community is in control and you open your schools and you do it carefully, there’s a good chance you’ll be OK. Don’t get me wrong – you’re going to get cases, your going to have to handle it and it’s going to be tough, but you have a chance to do it. But if we let this get out of control in August, I mean, then you know September is not going to go well.”
