Thread by @celinegounder

1/ THE NUMBER ONE #COVID #coronavirus topic right now? SCHOOL REOPENING. Here's my first of a couple threads on the topic, starting with some thoughts on K-12.

2/ K-12 shouldn't reopen until AFTER community transmission has been suppressed enough & gating criteria re: hospital/ICU/ventilator/testing/contact tracing/isolation capacity have been met. #COVID #coronavirus

3/ If you’ve still got widespread community transmission like in FL/TX/AZ, there’s no way to safely reopen. #COVID #coronavirus

4/ But… it seems that kids UNDER 10 years of age are at lower risk of infection, transmitting #COVID #coronavirus infection to others, and severe disease. This is based on epidemiological / clinical data & basic science.

5/ Some countries like Iceland (why not the US!?) have been doing widespread community-based testing for #COVID #coronavirus. This means they tested everyone, not just people with symptoms or known risk factors. So, they were testing people without symptoms, which is key.

6/ In Iceland, they found no kids under age 10 (compared with 0.8% of the general population) who tested positive for #COVID #coronavirus. nejm.org/doi/full/10.10…

7/ And among those who’d been exposed to COVID, 6.7% of kids under 10 tested positive vs 13.7% of those age 10 or older = about 2x the risk of infection in persons 10+ years-old. nejm.org/doi/full/10.10…

8/ The risk of infection increases with age. Under 10 year-olds are at lower risk. During its state of emergency, Iceland closed universities & colleges, but kept daycares & elementary schools open.
nejm.org/doi/full/10.10…

9/ A population survey in Vo’, Italy at the time the town went on lockdown found no kids under age 10 who were positive for COVID (compared with 2.6% of the general population). Some of these kids were living with adults who had COVID.
nature.com/articles/s4158…

10/ Data from the Netherlands suggests that within households, #COVID #coronavirus is mostly spread between adults and from adults to kids (not from kids to adults).
rivm.nl/en/novel-coron…

11/ Contact tracing data found no cases in which children under 12 were the source of COVID infection in the family. rivm.nl/en/news/initia…

12/ In NSW, Australia, contact tracers screened & tested close contacts of COVID cases in schools. Only 2 students out of almost 900 close contacts were infected. They found no evidence of students infecting staff.
ncirs.org.au/sites/default/…

12/ Across studies, kids appear unlikely to be #COVID #coronavirus index cases in households. They’re more likely to be infected by adults in household. NYC contact tracing data is bearing out the same pattern so far (PS: this is one of the many reasons to do contact tracing!)

13/ My residency classmate Dr. Supinda Bunyavanich (not on Twitter!) published this research in @JAMA_current: jamanetwork.com/journals/jama/…. She studied expression of ACE2 in nasal epithelium (i.e. the lining of the nasal passages).

14/ Think of ACE2 as the doorknob the #coronavirus uses to open, get into, & infect cells. Kids under 10 have a lot less ACE2 in their noses than do older kids & adults. jamanetwork.com/journals/jama/…

15/ This might explain why younger kids are at lower risk of being infected with #COVID #coronavirus & of passing on infection to others. jamanetwork.com/journals/jama/…

16/ Most countries that have re-opened schools have instituted some degree of staggering the start, stop, & break times within the school. Some have re-opened only for younger students. Some have re-opened only for older students. globalhealth.washington.edu/sites/default/…

17/ Super interesting table. Where we have data, it would seem that reopening schools for younger kids (Denmark & Norway) doesn't lead to significant increases in #COVID #coronavirus transmission. globalhealth.washington.edu/sites/default/…

18/ Where they reopened for older kids but not younger (Germany), they saw increased #COVID #coronavirus transmission, but no staff infections. globalhealth.washington.edu/sites/default/…

19/ Where they reopened for younger & older kids (Israel), they saw multiple #COVID #coronavirus outbreaks in schools. globalhealth.washington.edu/sites/default/…

20/ So long as there isn't widespread community transmission, perhaps elementary school should be in person for most (with specific exceptions + any famliy that prefers virtual should have the option), & middle/high school should be virtual for most (with specific exceptions).

21/ Bonus: Younger kids are less developmentally able to virtual learn vs older kids & they can't be home alone. More on this to come... but some initial thoughts.