Thanks to David for sending me this link to the summary prepared by the National Centre for Immunisation Research and Surveillance (NCIRS) on the investigations done regarding NSW school cases of COVID-19
Some thoughts to follow https://twitter.com/actinosproject/status/1254199579790028800

This is not a peer reviewed paper but a summary report on info to be delivered to schools today I believe. Paper will follow
As such it doesn’t have a truly scientific methods section which would include details of the PCR tests, cycle thresholds etc and of the antibody testing

15 schools, 10 HS and 5 PS had 18 COVID-19 cases (9 students 9 staff) identified between 5 March and 3 April 2020
863 close contacts were identified across those 15 schools
Defn close contact: face to face contact at least 15 mins or in same room with an infectious case 2 hrs

Doesn’t define infectious, presuming that is a symptomatic case?
Recent NEJM study from NH outbreak brings into question what we know about period when someone is infectious and role of presymptomatic and asymptomatic transmission. Good to read first https://www.nejm.org/doi/full/10.1056/NEJMoa2008457

Back to schools

School cases in Australia occurred when bulk of cases were being imported not during a phase of widespread CT so applicability to that situation is limited

The way conclusions are drawn in this summary gives me great pause
In both HS and PS they only swab tested 1/3 of the identified close contacts
HS: 235 tested by ‘swab’ were negative but one school had 75 close contacts antibody tested and 1 student had antibodies detected

The conclusion is written as “one of 695 individuals was identified to have been infected following close contact with a school case in these 10” HS
This is disingenuous
Only 1/3 were swabbed and 75 had antibody tests
Presume there is overlap in numbers from those groups

Not all exposed develop antibodies either so that is a further limitation

In the primary schools 6 cases identified (1 student and 5 staff)
Close contacts 137 students 31 staff n=168
Swabs from 1/3 n=53 contacts swabbed

One secondary case was identified as positive on nose/throat swabs from the 168 close contacts according to paper
Actually though it was 1/53
21 close contacts had serology
The same student positive on swab also had antibodies

Paper says “only one of 168 individuals was identified to have been infected following close contact with a school case in these five primary schools”

Again, can not say that as did not test 168 individuals
Only swabbed 53 and serology on 21 who obviously overlapped

So overall:

Study conducted in time when CT not his, kids began to be kept home
Low numbers of cases
Incomplete testing
Disingenuous conclusions intended to be more powerful than they are
Info on presymptomatic and asymptomatic transmission still developing

Hard to extrapolate any real conclusions under these circumstances and it is a shaky foundation on which to do so