A recent report, published on the CDC Morbidity and Mortality Weekly Report (MMWR) website: Outbreak Associated with SARS-CoV-2 B.1.617.2 (Delta) Variant in an Elementary School — Marin County, California, May–June 2021 detailed an outbreak of COVID19 that took place in May of this year in Marin County. At the time the school and region were following the current guidelines with schools open and in person but masks required while indoors.
An index case from an unvaccinated teacher who unmasked intermittently while teaching students, who according to the report, had good compliance with the masking policy infected a total of 27 cases that they were able to track down. The likely number was much higher but they were unable to track, trace and test all of the subsequent contacts. Further Phylogenetic tree classification of other individuals tested later showed identical versions of the virus suggesting this infection had a wider impact beyond the 27 detailed in the report
Classroom Layout
Timeline of Infections
Notably 6 were infected from a separate grade room and 8 additional cases of parents and siblings were infected of which 3 were fully vaccinated.
We don’t know the precise age or grade, but they fall in the kindergarten to Grade 8 range and all <16 and at the time ineligible for vaccination which at the time CDC recommendation was for vaccines for those 16 and up.
The team confirmed these cases were caused by the Delta variant by sequencing the virus from each of the individuals that had been identified as positive. At the time, the Delta variant was still emerging but had not reached the levels we are seeing now
What can we learn from this detailed study of an outbreak
- 🙏No blame reporting is essential to improving our understanding and science
- ➡️The unvaccinated are at increased risk of getting COVID19 even more so with the Delta Variant
- ✅The unvaccinated increase the risk of infecting others
Raw Transcript
Nick van Terheyden
Hi, this is Dr. Nick on the incrementalist here with incremental insights for better business better health.
Fred Goldstein
And I’m Fred Goldstein with get accountable health here helping companies look at their employee health improvement programs, as well as work with Nick and others on COVID in the return, so this week, Nick, interesting report. Last week on September 3 out of the CDC, there mm wr talked about the outbreak associated with SARS Coby to delta variant in an elementary school in marine County, California, we had a request by Andy, one of our colleagues to take a look at this. And obviously, if you ever have a request and would like us to look into something, please reach out to us, we’d be happy to do that. Anyhow, let’s get to this report, Nick, and then I’d love your comments on this. So this was a marine county Elementary School in a district with 30,000 students, it had been fully open last year, obviously following certain requirements. And up until the point of this study, there had only been 12 total schoolwide infections since August of 2020. This actually occurred at the end of the school year, and delta was just coming out. We didn’t know a lot about it. And it turned out that there was an unvaccinated person, a teacher who turned out to be the adult index case, who was not wearing a mask a few times, and during a two day period had symptoms, but had come into the school. And it apparently been at some events three days prior to this. He was one of only two of the school’s teachers who were unvaccinated. and subsequent to this index exposure 12 of the 24 kids in one classroom were infected. All of the infected students were under 12. And obviously unable to get vaccinated. And in looking at the original classroom, Nick, I was thinking about this. And it’s really similar to the earlier reports we had seen from the Chinese restaurant that we brought up months and months, I think it was sometime last year actually. So throughout this period, all desk are separated by six feet good stuff, the students were seated in five rows. And interestingly, again, the attack rate in the two rows seated closest to the teacher’s desk was the highest at 80%. While 28, or four of the 14 in the three back rows got infected, in the end, 27 total cases, including siblings, and parents, some of these were associated with a sleep over, etc. There were also for parents that were infected. three of the five adults were fully vaccinated, they all experienced some symptoms, no hospitalizations, and it was sequenced, which was great. They follow that sequence, they determined it was all Delta 11 were identical, including six from the original classroom. So again, we’ve got this outbreak indoors, unmasked, partially unvaccinated teacher, what’s it mean, Nick, what do we get out of this thing?
Nick van Terheyden
You know, so first of all, thanks to Andy for asking, I think a great topic to discover and dive into. The first thing I would say is it’s easy to pass judgment. And you know, I think people’s reaction depending on what side of the fence you come from, you know, is maybe pejorative to the teacher because he pulled his mask down, he wasn’t as compliant. And the first thing I would say is we have to take a lesson from the airlines where it’s a no fault, root cause discovery, we would not have this detailed amount of data, if there was a, you know, witch hunt for people that reported. And it’s easy to say, Well, he pulled his mask down, and he’s unvaccinated. We know nothing about that individual as to whether he can have a vaccine, so he may not be eligible. And when it comes to the masking, it’s easy to say, you know, you should just always wear it. Well, I challenge anybody to walk around anywhere at any time in the public, and not see people doing this whole thing. I even do it. It’s very difficult to wear these masks. And you know, this is an individual who’s teaching younger age kids trying to communicate, I passed no judgment on this. The other thing was he was symptomatic. And you can say, Well, he shouldn’t have come in. And again, I take the positive view of this and say, if he’s like me, he may have had a nasal drip a cough didn’t understand or did not comprehend the fact that he was infected. He clearly did at some point, and notified the authority. So in my view, this is not about the teacher. This is about what we can learn. And as you rightly detail, you know, the critical point here one, an unvaccinated individual was the index case that’s spread to this class. So vaccination is our primary cause or methodology for defense. masking does work, but it has to be well followed. And you know, this pulling things down and you see it all the time. I mean, I have trouble trouble hearing people, I see it on the airlines, you know, the somebody’s leaning over to get their drinks over and they can’t hear and they pull them out. It’s just a natural human habit. This is not a witch hunt on individuals. It’s all about informing and helping people get to the right decision making. And then the other thing I would say that’s interesting, and you rightly point out, we went into the detail of that restaurant, but it was also the South Korean restaurant where we saw that distance of transmission. And whilst the transmission was lower in the back rows, it still occurred. And this is with the Delta variant, which we see is far more transmissible. So, you know, what do we get from this? Well, first of all, we have to be testing. I think the most important thing here that I get out of this is, we know vaccines work, we know that masks are absolutely preventative, but they have to be worn by both parties even. You know, for folks that don’t want to we have to essentially protect our community. And then we need to be testing and testing as frequently as necessary to be able to determine where these breaks and these infections come from. So I’m just delighted. I love science, I love data, it gives us more information. The sad thing is, it feels like it’s a little bit of a repeat on formation that we already got from the church, from the restaurant case study and also the call center, I think as well.
Fred Goldstein
Right? Absolutely, it really does point to the importance of doing these things. And I would also point out that we’re using HIPAA filters in the in the rooms, and they did have the doors open. So there were efforts clearly to try and control this, which they ultimately were able to do. And they also point out that any spread beyond the school was probably limited because the county has a very high vaccination rate. So you didn’t see this thing just explode out into the community, like we’ve seen in other cases, with some rapid growth in infections.
Nick van Terheyden
And the other thing that they did, which was you know, in addition, they did the phylogenetic sequencing to track it back, they didn’t get the teachers original sample to confirm it. But essentially, the similarity of the genetics allowed them to link all of these cases together, there was this one other separate class couldn’t determine it. And your point is exactly right. They were doing all the right things, they had separation, these groups got it, and they got it in potentially outdoors. They were separated, you know, they had all of these factors in play. And then you had this transmission out into the community, which you know, is part of what we’re trying to prevent. So we have to follow the guidelines. vaccination is the key. But the other thing that we need to be doing at this point is we’ve got to be wearing face coverings on both sides of that equation. indoors. Absolutely. Well,
Fred Goldstein
thanks so much for diving deeply into this, Nick, really appreciate it. And thank you, Andy for submitting the question. If anyone else would like to you can get us either via Twitter or LinkedIn or send us an email happy to take a look at it and report on it. This is Fred Goldstein with accountable health. If you’d like more information, please go to accountable health. llc.com
Nick van Terheyden
and this is Dr. Nick, I’m the incrementalist here with incremental insights for better business better help.
