Schools are about to open. Some with little to no mitigation measures in place (looking at you, Texas). What can we learn from summer superspreader events among kids? And, how has Delta changed the game?
Summer Camps
In late June 2020, 627 people attended a sleep-away camp in Georgia. This included 137 trainees, 127 staff, and 363 campers aged 5-17. Two studies were just published (here, here) describing, in great detail, the superspreader event. What happened?
Before arriving, everyone was required to have a negative COVID19 result within 12 days. Upon arrival, attendees were placed into cohorts by cabin, which equated to 28 cabins (or 28 cohorts). The organizer’s hoped (and assumed) that kids would only interact with other kids in the same cabin.
Five index cases (infected in the community) arrived to camp (2 were symptomatic). All 5 index patients were in 5 separate cabins. The following days a large outbreak ensued, infecting a total of 351 people (52% attack rate). The epi curve peaked 11 days after orientation.
450 (70%) of the attendees were interviewed by CDC, so we could fully understand how the virus spread. This is what they found:
No cabin was spared from the outbreak. The cohorts obviously didn’t work. 88% of attendees reported direct contact, such as hugging, kissing, playing indoor sports, or traveling in vehicles with people outside their cabins.
15% of trainees and staff members reported always wearing a mask during camp, compared with 5% of campers.
A senior staff member described daily vigorous singing and cheering during the camp session.
The second study analyzed what happened once a subset of campers (224 kids aged 7-19 years; 88% asymptomatic) went home. The 244 kids had a total of 377 contacts at home.
Out of 377 exposed household contacts, 48 (12%) tested positive
Transmission occurred in 35 of 194 households (18%); in these households, the secondary attack rate was 45%
10% of household cases were hospitalized
Length of hospital stay was 5 to 11 days
All hospitalized cases were 18+ years old
When the secondary cases were interviewed by the CDC…
67% said they had maintained physical distancing
34% said they had always worn masks around contacts during the infectious period after they returned home
How has Delta influenced superspreader events?
Delta is so new that peer reviewed studies are few and far between. Instead we have anecdotal evidence of Delta superspreader events at summer camps. The details have lots of epidemiologist holes, but we can an idea of what happened. For example…
In late June 2021, 450 staff and school-aged kids (6th through 12th graders) attended a church camp in Galveston Texas. On June 27, the first case was reported to the health department. Of the 450 attendees, 156 tested positive (35% attack rate); 20 were breakthrough cases.
As expected, the superspreader event bled to the community, with at least 90 community infections due to the original outbreak.
No one was hospitalized
Delta was responsible for the outbreak
From June 13-17, 2021, teens and adult staff members attended a summer camp in Schuyler County, Illinois. Vaccination status was not asked, masks were not required, and only a handful of attendees were vaccinated (even though everyone was eligible)
85 tested positive for COVID19 (we don’t know the denominator or how many were exposed, so we can’t calculate attack rate)
One young, unvaccinated attendee was hospitalized
This, too, bled into the community. 2 of these index cases left for a conference, which resulted in 11 additional cases
We do have one published study describing a Delta superspreader event among kids. From April 15-May 3, an outbreak occurred at an Oklahoma gymnasium.
194 people were exposed and 47 (24% attack rate) cases were identified: 23 gymnasts and 3 staff members
The median age of a case was 14 years (range: 5–58 years)
2 adults were hospitalized (both unvaccinated). One required the ICU
The 47 cases had 80 household contacts. Among the 80 contacts, 42 were infected (53% attack rate)
Among all cases, 85% were unvaccinated (majority were eligible), 6% partially vaccinated, and 9% fully vaccinated
Bottom Line
Using the case studies, we can start extrapolating important patterns:
In the four aforementioned case studies, one adolescent ended up at the hospital. Kids continue to be relatively resilient from severe disease. However, hospitalization is a pretty low bar to set. We know this isn’t the only outcome.
School-aged children continue to efficiently transmit COVID19 to household members and the surrounding community. And this transmission directly results in hospitalizations.
Delta is more transmissible than previous variants, leading to a higher attack rate. For example, as pointed out by CDC, the household attack rate in the gymnastic outbreak (53%) was higher than secondary attack rates associated with previous variants (17%).
Another common theme: Effective public health mitigation measures (masks, distancing, vaccinating, etc.) were consistently ignored.
Is this a preview for what’s to come in Fall? Only time will tell.
Love, YLE
ok. two hours after the announcement went out on friday the 13th, (my wedding anniversary) i had the shot. not that hard. they asked are you immunocompromised? i said, i have stage four cancer, whatchoo think? they said come in and get a shot of moderna, which is what i asked for. so at 4:45 pm, i got the shot, exactly six months to the day from the second shot.
did i have to prove i was sick? no. they didn't ask for proof. how's it feel? arm was sore, i felt crummy for two days, then i was good. the second shot was twice as sucky. extrapolating on the sucky scale, i'm guessing i had half the spunk of the second shot left. no scientific practice was used in the making of this SWAG.
should you get it? fork yeah.
Public school will be starting in the next month for my kids, luckily for me mine are 12 yo twins and fully vaccinated as of mid-June. What do you see as most likely safe measures for kids like mine going back to school? My initial thought is to mask up, even if their friends/teachers aren't, but if they are in the minority they're also going to be exposed to middle-school kids who could very well not understand everything and I'd hate for my kids to be attacked and picked on for wearing masks when so many others aren't. I worry about their physical health, but also their mental health. I'm torn as to being as safe as I can (stay home another year alone), vs. wearing a mask in school, vs. going un-masked when in class since they're vaccinated. We have no concerning health conditions and everyone's fully vaccinated at home. I feel like we're in the best possible position to be OK, but I am still concerned.