🧵🧵Australian church choir singer #covid19 outbreak now in CDC EID
•no masks
•no ventilation systems
•transmission >50 feet—> airborne
•confirmed via genome sequencing
•12 secondary cases detected out of 508 (2.4%), although only 434 were tested

Source: CDC EID journal
2/ So the index case was a choir singer who started to feel sick on July 16th; sang at four 1 hour services on the 16th & 17th from a choir loft elevated 11.5 feet above the congregation #covid19
3/ The secondary cases reported no other contact with the singer.

Video recordings were also used to confirm their seating positions relative to the index case as well. #covid19
4/ Ventilation was assessed- seems like it wasn’t very good.

Ironically this was right around the time in late July when @zeynep piece in @TheAtlantic came out on the same topic— “why aren’t we talking more about ventilation?”
5/ Interesting that there were no cases reported that only attended the July 17th session.

Also, the secondary attack rate is still somewhat low at 2.4% across 4 events (5.8% at one of the 4) — other choir singing-type events have had much higher
6/ Many factors go into this though

85% had follow up for at least one test within 17 days after exposure

Still- as we know- without serial testing, you are bound to miss some cases that then are marked as “negative”

Also- would suspect the actual size of indoor space matters
6.5/ Being in a small room w/ an infected choir singer v being spread out in a large hall with one singing from a loft is going to pose a different level of risk— would also expect this reflected in diff transmission dynamics/ number secondary cases etc #covid19
7/ I think this study does add more important evidence—> airborne transmission of #covid19 can & does occur, esp under the “right” circumstances- poor ventilation indoors w/ an infectious case where masks are not worn (& singing here, but aerosolize even just talking)
8/ So, important to remember again that there are no magic “6 foot” rules with this

The further away you are from someone else, the better

Better ventilation

Shorter duration of time when possible

Masks (esp if unvaccinated in public settings) #covid19
9/ Link to the full paper here:


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More from @AbraarKaran

5 Apr
🧵1/ This is a tragic story in @washingtonpost — we have seen, treated, & continue to treat many cases just like this.

When people share their tragedy, they are sacrificing to remind us all that the epidemic is not just numbers; those numbers are people. They are families. Image
2/ Who do we blame?

Many who got sick *couldn’t avoid it*- they weren’t protected.

Others had the privilege to avoid risk- worked from home, had $ etc.

And some blatantly chose to actively go against advice like wearing a mask, hurting themselves & others.
3/ The piece here specifically implicates the latter groups- where there is some truth to the idea that people’s choices contributed to spread. How much is unclear- partly because many infections are actually in the former group- that couldn’t stay home, that worked frontline etc
Read 5 tweets
4 Apr
🧵1/ In a pandemic, we have two urgent interests: that life saving vaccines/ treatments be created, manufactured, & distributed, and that the disease be quickly contained/eliminated worldwide without a potentially catastrophic resurgence. #covid19
2/ The financial interests of pharmaceutical shareholders accord with our first interest, but not always with the second.

Product allocations go to the highest bidders, rather than to where need is greatest or the pandemic may be contained most effectively. @ThomasPogge
3/ The system as it stands is designed to fail, because public health is a secondary goal behind financial recuperation & explicitly financial profit

In a pandemic, it can’t be that way.

But I don’t need to tell you all this- you have been watching it unfold already. #covid19
Read 10 tweets
1 Apr
“While more than six million of the country’s 18 million people have been vaccinated, a surge in infections has left intensive-care units operating with few beds to spare and the system at a breaking point.” From Chile @nytimes

2/ “Dr. Francisca Crispi, a regional president of Chile’s medical association, said that 20 to 30 percent of medical professionals in the country had gone on leave because they are so exhausted.”
3/ “No one questions that the vaccination campaign is a success story,” she said. “But it conveyed a false sense of security to people, who felt that since we’re all being vaccinated the pandemic is over.”
Read 4 tweets
30 Mar
1/ Sharing new piece: we have learned a lot this year about the deficiencies of the ‘test,trace, isolate’ system, but it is still going to be needed to burn out the epidemic once case numbers are brought down further.

W/ @RanuDhillon
washingtonpost.com/outlook/2021/0… Image
2/ With most of the focus on 💉💉 right now (as it should be)— our other pandemic tools like Test, Trace, Isolate (TTI) have taken a backseat.

Yet, they are still crucial to stopping the #covid19 epidemic- but we need to do each of them better.
3/ Having this infrastructure in place will be essential for future infectious disease outbreaks/pandemics.

I expect TTI will become especially relevant again this summer to stop ongoing transmission chains once we have vaccinated a majority of country

Cc @cshea4 @PostOpinions
Read 4 tweets
29 Mar
Hoping for less deadly surges

1/ An important piece of the puzzle that some have pointed to: 49% of 65+ in our country have been *fully vaxx*; 73% have received at least 1 dose

We know age is single most significant risk factor in mortality. #covid19

2/ While proposed plans to simply isolate the elderly are largely unachievable/ not how societies fundamentally function-- what many of us do agree on is that vaccinating the elderly as a priority group is critical; and we are doing it well.

3/ With real world data from @CDCMMWR today showing significant protection even 2 weeks after just the 1st dose of mRNA vaccines, I am optimistic that we should see a further notable reduction in mortality even w/ subsequent #covid19 surges

Read 5 tweets
29 Mar
Excellent news from @CDCMMWR today!

Under real-world conditions, vaccine effectiveness of mRNA (Moderna, Pfizer) vaccines:
-90% after 2 doses
-80% after one dose (both measured 14 days after dose) #covid19

2/ "Prospective cohorts of 3,950 health care personnel, first responders, and other essential and frontline workers completed weekly SARS-CoV-2 testing for 13 consecutive weeks."

Data collected from eight U.S. locations during December 14, 2020–March 13, 2021 #covid19
3/ "CDC routinely tested for SARS-CoV-2 infections every week regardless of symptom status and at the onset of symptoms consistent with COVID-19–associated illness."

Gets at one of the biggest questions since the vaccines came out: extent of reduction in asymptomatic cases
Read 6 tweets

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