Fact Check My Feed: Are Kids Really COVID-19 ‘Super Spreaders’?
This story is part of Science Friday’s coverage on the novel coronavirus, the agent of the disease COVID-19. Listen to experts discuss the spread, outbreak response, and treatment.
Late last month, as parents and teachers were gearing up for an unusual and stressful start to the school year, conflicting media reports of coronavirus transmission among children started populating our news feeds. One headline proclaimed, “New study suggests children may be COVID-19 ‘super spreaders,’” while other articles cited researchers saying the opposite. But the disagreement didn’t stop there. Some outlets reported that very few preschoolers are catching the coronavirus, while others cited a study that suggests children younger than 5 may harbor up to 100 times as much of the virus as adults.
Angela Rasmussen, associate professor in the Columbia University Mailman School of Public Health, joins Ira to talk about the data behind these stories in a round of Fact Check Your Feed. She also explains new testing guidelines issued by the CDC, and a misleading report on the coronavirus death rate.
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Angela Rasmussen is a research scientist at VIDO-InterVac, the University of Saskatchewan’s vaccine research institute in Saskatoon, Saskatchewan.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. As parents and teachers gear up for an unusual and stressful start to the school year, conflicting media reports of Coronavirus transmission among children have populated our news feeds. Here’s one headline. New study suggests children may be COVID 19 super spreaders. While other articles cite researchers saying just the opposite.
These conflicting media reports means it’s time for another round of fact check your news feed. Joining me again to help clarify the studies of kids and Coronavirus transmission as well as a few other misleading claims circulating online right now is Dr. Angela Rasmussen, Associate Research Scientist in the Columbia University Mailman School of Public Health. Welcome back to Science Friday.
ANGELA RASMUSSEN: Thanks for having me back, Ira.
IRA FLATOW: So on top of an already confusing start to the school year for many folks, we’ve been seeing these conflicting news reports about how kids may or may not be spreading the virus. What is the real answer to this question, Dr. Rasmussen? Do we know?
ANGELA RASMUSSEN: Yeah, so this is a tricky one to sort out because oftentimes these reports appear to be conflicting. And those differences might just be differences in circumstance of the population of kids that are being studied in any given paper or report.
The things that we do know is that children can definitely become infected with Coronavirus, and they can spread Coronavirus as well on both the people in their households, other adults, as well as to other children. There was a summer camp in Georgia in June in which over 200 kids spread the virus among each other as well as to some adults who were acting as camp counselors and older teenagers who were also running the camp.
So we know for sure that kids can definitely become infected. They can definitely spread it. As to whether their viral loads are higher than adults, that was one study that showed that certain kids had higher levels of virus RNA than adults. But overall, all the data that we have shows that kids at least have as much virus as adults. And this varies from kid to kid, just like it varies from adult to adult.
So overall, the things that we really do know that we have consistent evidence of is that kids can become infected, they can spread it to others, and in some rare cases, they can get very, very sick from it.
IRA FLATOW: There was also a report about summer camps in Maine. I think there were four summer camps that showed how effective social distancing and wearing of masks were in preventing the spread from kid to kid and from kid to counselor and vise versa.
ANGELA RASMUSSEN: That’s absolutely right. Those summer camps in Maine really show how important these risk reduction measures are to take. Those measures were not taken at the camp in Georgia, I believe. And it also kind of gives us some insight as to why some of these reports might be conflicting and why it’s so important to look at the circumstances that are in each situations.
Each study like this is really reporting a different set of circumstances. And just because there was more spread or less spread or higher viral loads or lower viral loads in one population doesn’t mean that these are completely conflicting. Again, there are different circumstances at play and there are different people at play, too.
So I think that it’s a mistake to present two studies that have similar situations and say that they’re conflicting with each other. It’s really just a report of two different situations.
IRA FLATOW: Let me tease this apart a little more because there’s this study from JAMA Pediatrics that looks at viral load in kids. And some news outlets report that it’s as much as adults. Some outlets report that it can be as much as 100 times more than adults. What’s going on here?
ANGELA RASMUSSEN: So that study, again, is one slice of a particular population. And it also looks at viral RNA. I don’t believe that study actually looked at infectious virus. So you really have to be careful when making conclusions about the viral loads because you’re looking at the viral genetic load. You’re not necessarily looking at differences in the amount of infectious virus that would actually be virus that you could transmit to somebody else.
I think that what we can conclude, we already know that in different people at different points in infection, there will be different viral loads. That can be influenced by a lot of different variables. It could be a person’s susceptibility. How good of a host they are, effectively, for the virus. It could be the dose of virus that they were infected with that could distinguish viral loads in one person versus another. It could also be the time since they were infected. They could be in different places in their infection. Their immune system could have different capacities for controlling the infection.
So it’s important to understand that loads in people are going to cover a certain range. I think that with a study of a couple people, it’s very difficult to say conclusively that viral loads are 10, 100, 1,000 times higher in one group than another. I think it’s important to say that they are at least within the same ranges.
And that, again, suggests that kids are not somehow more mysteriously resistant to this virus than adults. They can be infected and they can have viral loads that are at least equivalent or in equivalent range to adults.
IRA FLATOW: Would it be fair to say that we don’t have as much data on kids and the Coronavirus as we do on adults?
ANGELA RASMUSSEN: I think that’s fair. I think that in– one thing we also know about children is that many of them have very mild infections, or potentially asymptomatic infections, which means that there are probably a lot of cases in kids that have been undiagnosed. So we just haven’t had as much opportunity to study them.
A lot of what we know about patients are patients who have become very sick and have been hospitalized. And obviously, it’s easy to find those patients because they’re showing up at the hospital. They need care and they’re very sick. Not as many kids are doing that because they don’t, generally, get as severe of disease. We’re not going to be able to study as many of them.
IRA FLATOW: I think one of the confusing issues here seems to be this relationship between how much viral load kids have and how much they’re actually spreading the virus. I mean, do we understand that dynamic yet?
ANGELA RASMUSSEN: Not really. Although, we do know that kids– there was one study that showed that at least in symptomatic children, they did detect infectious virus in their nasal passages or their nasal swabs. So some kids, at least, are shedding virus that could be capable of infecting somebody else. I can’t personally see any reason why kids would be less transmissible or less contagious than adults. If they have the same viral loads as adults, then presumably, they’re shedding as much virus.
But this is an area that we don’t have a ton of data for. Early reports that kids were less capable of transmitting it were based really on epidemiological studies of households in which they deduced that the children were not spreading it to other members of the household. But of course, there are exceptions to that. So that data might, again, appear to be conflicting. I think that it’s really hard to make very general conclusions based on circumstantial epidemiological investigations like that.
IRA FLATOW: And so is there anything we can take away from this data and apply it to the start of the new school year? I mean, what should teachers and parents think about all of this?
ANGELA RASMUSSEN: Well, teachers and parents should definitely not think that children are immune or more resistant to the virus. Just because they don’t develop a severe of disease, that doesn’t mean that they can’t be infected and it doesn’t mean that they can’t bring the virus home with them to transmit to other people in their household. It also doesn’t mean that they would be incapable of transmitting it to faculty and staff in schools.
And in general, we– I think a lot of the discussion about schools has assumed that schools are an isolated bubble that is separate from the rest of the community, and they’re really not. If children are getting infected, whether outside of school or in school, those children are still part of the same community and they’re capable of spreading the virus within that community.
So we need to stop thinking of schools as a separate space or children as a special population of people who are less susceptible. We need to take the same precautions with preventing transmission in schools as we do within the rest of the community.
IRA FLATOW: We talk a lot about schools, but I know parents– there are parents all over who are sending their kids back to daycare, their pre-school kids. Should we think about the same precautions and the same transmission rates for these younger children?
ANGELA RASMUSSEN: Yeah, with younger children, especially, it’s really difficult. Try getting a three-year-old to wear a mask the correct way, and being in close physical proximity to each other, especially an indoor environment. We should definitely try to implement some of those protections. But I think another thing that can be done with day cares is to really limit the number of kids that are going there in the first place.
Maybe having a smaller daycare setting or being [INAUDIBLE] groups of daycare kids so that there are not as many people in one given space might help with being able to try to implement as many measures as possible to reduce transmission in those environments.
IRA FLATOW: I want to touch on a news item and get your opinion about a couple of things that have been circulating just this week pointing to CDC data that reports only 6% of COVID-related deaths are actually from the virus itself. I mean, this statistic is getting a lot of heat and just flies in the face of everything we’ve been talking about before, doesn’t it?
ANGELA RASMUSSEN: It really does. And unfortunately, that statistic is cherry picked from that data set, which was describing the causes of death as reported on death certificates. Death certificates usually have several lines in which a coroner or the person filling– completing the death certificate can put causes of death. And in many cases, they will say some– what the cause of death was, either heart failure or respiratory failure or something like that due to COVID 19.
This has been misinterpreted to suggest that only the first cause of death is the cause of death and that had nothing to do with COVID 19. The idea that people are incidentally infected, but they’re dying from something else that they would have died from anyways. And that’s just simply not true. There are a number of diseases in which people might die from a secondary condition that was the direct result of the first disease.
HIV is a great example of this. One of my colleagues who studies HIV pointed this out to me, that people often with AIDS die of a secondary pneumonia, they die of cancer. But that cancer was the direct result of them being infected with HIV. We would never say that this person didn’t have AIDS. They didn’t die from HIV infection. They did die from AIDS. They just died specifically from a pneumonia that was caused by the HIV infection.
And this is the same case with these COVID deaths. So if somebody dies of respiratory failure due to COVID 19, they weren’t going to have that respiratory failure even if they had other comorbidities if it weren’t for them being infected with SARS Coronavirus 2.
IRA FLATOW: The CDC recently issued new guidelines for testing of asymptomatic people. We’re all about data here, so did the CDC cite any studies that would support that change? Tell us what that change was and why it was motivated.
ANGELA RASMUSSEN: I can’t say why it was motivated because the CDC has not disclosed that. But what the change was that the CDC is no longer recommending testing of people who believe that they’ve been exposed to Coronavirus or know that they’ve been exposed to Coronavirus if they are asymptomatic.
And there really is no basis in evidence for making this decision. The CDC did say to a reporter at the New York Times that the decision wasn’t made to conserve testing resources. So that leads to a lot of questions as to why they made that decision. Because what we do know from the evidence is that there is a substantial amount of transmission from pre-symptomatic people. And those are people who are eventually going to get sick with COVID 19, but don’t have any symptoms when they are producing and shedding the most virus.
So it’s really dangerous to suggest that people who believe that they’ve been exposed to Coronavirus should not seek testing. Because if those people are actually infected and they don’t know it, they might not take the necessary precautions to avoid transmitting it to people while they’re in that pre-symptomatic stage.
And it’s really, really troubling that the CDC has released this guidance. Because the obvious conclusion that many people have come to is that it’s politically motivated rather than motivated based on evidence and good public health practices.
IRA FLATOW: I’m Ira Flatow. This is Science Friday from WNYC studios. Talking with Dr. Angela Rasmussen, Associate Research Scientist in the Columbia University Mailman School of Public Health talking about fact checking your feed.
Speaking of the CDC, do you think the CDC has lost respect as an independent reliable source of information?
ANGELA RASMUSSEN: I think to some degree it has. I think that it’s important that people understand that the CDC does many things. They do scientific research. They collate all this data. Like, for example, the death certificate data, and they report that publicly. And then, they also make policy. The CDC is still doing– there are great scientists who work at the CDC. There are great epidemiologists who work at the CDC who are doing great work.
The problem here is in the policy arm of things where they’re making guidance that’s more based on political considerations than scientific evidence. It really does undermine their credibility for releasing that guidance. Because you can’t really– if you can’t trust that the CDC is providing guidance on really critical public health issues in a way that’s based on the evidence that they gather and analyze, that causes you to question what their motives even are.
And I think that, for many scientists, it’s been tremendously disappointing to realize that this premier agency for dealing with infectious disease threats is compromised in this way.
IRA FLATOW: Lastly, I want to bring up a New York Times article you were quoted in that suggested that Coronavirus tests could be less sensitive. Why would we want that?
ANGELA RASMUSSEN: Yeah, so I think that this has been somewhat misinterpreted. Because the headline of that article said that the Coronavirus test may be too sensitive. And this is really referring to the fact that the PCR test of the molecular diagnostics test that is being used can detect viral RNA even at very low levels. And so people who’ve recovered from Coronavirus will test positive sometimes for many days sometimes even weeks.
And that’s residual virus that low levels– residual virus genetic material that’s being detected and not actual live infectious virus. The idea that tests could be less sensitive is really an intriguing one in terms of increasing our testing capacity and putting testing, really, into the hands of people themselves allowing them to make real time actionable public health decisions.
That’s the idea that maybe the PCR test is so sensitive it’s picking up all this non-infectious virus. If you had a test that you could do at home that was less sensitive, but would still pick up high enough levels of virus to be transmitted, you could, say, test yourself in the morning and decide not to go to work. Because all of a sudden, you have high enough viral load that you might be infected. You might be shedding. So time to isolate yourself and call your medical provider.
I think that that would be incredibly useful for not only empowering people to engage with public health and to take their health into their own hands, but also it would really solve a lot of the problems that we’ve had with testing capacity and turnaround time. It would allow people to really find out, on a daily basis or a routine basis, anyways, whether or not they might have been infected and might also be contagious.
So I think that there really is an important place for some of these rapid do-it-yourself at home tests. We just need more of them to become available. We need the FDA to consider approving more of these tests.
IRA FLATOW: Dr. Rasmussen, always a pleasure to have you on. Thank you for taking time to be with us today.
ANGELA RASMUSSEN: My pleasure, Ira. It’s always great to be here.
IRA FLATOW: Dr. Angela Rasmussen, Associate Research Scientist in the Columbia University Mailman School of Public Health.