Amazing study of school transmission from Spain 🇪🇸
Shows a clear age dependant transmission gradient - the older the children, the more transmission
Lowest rates occurred in unmasked pre-school children
Overall R*=0.4 in schools
Let's take a look!
1/
journals.lww.com/pidj/Abstract/…
Shows a clear age dependant transmission gradient - the older the children, the more transmission
Lowest rates occurred in unmasked pre-school children
Overall R*=0.4 in schools
Let's take a look!
1/
journals.lww.com/pidj/Abstract/…
This study used data from the Catalan school surveillance system
All contacts within school bubbles are tested following a positive index case
Linked cases determined by onset within 10d of index
They matched this data against the wider health surveillance system data
2/
All contacts within school bubbles are tested following a positive index case
Linked cases determined by onset within 10d of index
They matched this data against the wider health surveillance system data
2/
Mitigations included masks from age 6 upwards, school bubbles, and increased ventilation
They found data matched well between school and wider health surveillance
This is a massive study of roughly 15,000 index cases within schools
Let's take a look at the results!
3/
They found data matched well between school and wider health surveillance
This is a massive study of roughly 15,000 index cases within schools
Let's take a look at the results!
3/
The main finding was of a clear age dependant gradient on transmission within school bubbles
R* = 0.2 in pre-schools up to 0.6 in high schools
4/
R* = 0.2 in pre-schools up to 0.6 in high schools
4/
A substantial proportion of index cases transmit to no secondary cases (left) - 78.5% of primary and 71% of secondary school
A higher number of index cases found in the older children also corresponded with a higher number of linked secondary cases (hence higher R*) (right)
5/
A higher number of index cases found in the older children also corresponded with a higher number of linked secondary cases (hence higher R*) (right)
5/
As with many studies of COVID-19, transmission was over dispersed (lots of super spreading)
14% of cases in primary and 17% in middle school resulted in 80% of transmission within bubbles
6/
14% of cases in primary and 17% in middle school resulted in 80% of transmission within bubbles
6/
The strengths of this study are that bubbles were screened - so all students tested. Therefore it is unlikely secondary cases were missed.
Data was also linked to wider health surveillance with a good match, so we can have good confidence here
7/
Data was also linked to wider health surveillance with a good match, so we can have good confidence here
7/
Caveats are asymptomatic index cases resulting in asymptomatic secondary cases may have been missed - it is unlikely large outbreaks could have gone unnoticed in this context
This was pre Alpha or Delta - as a rule of thumb you could probably double R* for Delta vs Wild type
8/
This was pre Alpha or Delta - as a rule of thumb you could probably double R* for Delta vs Wild type
8/
An extraordinary study from a great team, confirming R*0 surprisingly low in the school environment, and increasing in an age dependant manner.
In the era of vaccines, we can hope for fewer introductions from outside school too
9 end/
In the era of vaccines, we can hope for fewer introductions from outside school too
9 end/
• • •
Missing some Tweet in this thread? You can try to
force a refresh
