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Finally got around to starting in on the old measles articles. These are the ones that show that measles is "magic" and "airborne" whereas very little else is.
So, one infected child in a doctor's waiting room infected 7 others. The rate in unvaccinated kids very high.
So, one infected child in a doctor's waiting room infected 7 others. The rate in unvaccinated kids very high.
Of particular note, they did airflow studies and the "droplet nuclei" were throughout the office. Furthermore, lack of ventilation already known.
So what on earth are the people against aerosol actually arguing against?
So what on earth are the people against aerosol actually arguing against?
In fact, this whole article feels like 2020, except that it was written 45 years ago.
This whole blurb sounds very familiar.
I am glad we continue to do the same things again and again and again while people die.
This whole blurb sounds very familiar.
I am glad we continue to do the same things again and again and again while people die.
A few posts back I noted this article says airborne spread of measles is unusual.
Compare this to the current crop of comments saying "airborne spread of SARS2 is unusual", keeping in mind what those same ppl say about airborne measles.
Compare this to the current crop of comments saying "airborne spread of SARS2 is unusual", keeping in mind what those same ppl say about airborne measles.
Here is another report, from another doctor's office. Same comments: everybody thinks by droplet, but there is increasing evidence it is airborne, etc. etc.
I'd suggest this is exactly descriptive of the current debate with the stalwart dogmatic adherents to droplet theory, except this was written in 1985 about measles, and it's now 2020.
In 1935, public health debated the transmission of measles.
Some believed it was ever present in the air ("miasmatic") and others believed transmitted person to person.
The former were not inclined to do anything, because quarantines wld not work.
We learned was transmitted.
Some believed it was ever present in the air ("miasmatic") and others believed transmitted person to person.
The former were not inclined to do anything, because quarantines wld not work.
We learned was transmitted.
First article is Bloch: https://pubmed.ncbi.nlm.nih.gov/3982900/
Second article is Remington:
https://pubmed.ncbi.nlm.nih.gov/3974036/
Second article is Remington:
https://pubmed.ncbi.nlm.nih.gov/3974036/
I'll add this re measles:
Often said that measles has such a high R0 value (12-18), it must be airborne, whereas SARS2 is much lower (2.5-3.5).
A few issues.
1. R0 is measure of infectivity not mode.
Often said that measles has such a high R0 value (12-18), it must be airborne, whereas SARS2 is much lower (2.5-3.5).
A few issues.
1. R0 is measure of infectivity not mode.
2. measles R0 (Reff) varies widely. The shaded area is the often cited 12-18. (Guerra 2017 https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(17)30307-9/fulltext)
Another:
And one more:
Authors' conclusion is R0/Reff values are context dependent.
Think of the Skagit Choir situation - we've seen widely divergent effective repro numbers ("highly dispersed").
Think of the Skagit Choir situation - we've seen widely divergent effective repro numbers ("highly dispersed").
2. Experts have noted this highly dispersed R0 for SARS2, and estimate that true R0/Reff may not 2.5-3.5 but in fact double that
2a. Sanche, from February as preprint and July in CDC journal said median R0 of 5.7. https://pubmed.ncbi.nlm.nih.gov/32255761/
2a. Sanche, from February as preprint and July in CDC journal said median R0 of 5.7. https://pubmed.ncbi.nlm.nih.gov/32255761/
2b. Another article by Ke (w/Sanche), now in preprint, saying "This suggests a highly infectious virus with an R0 likely between 4.0 and 7.1. " https://pubmed.ncbi.nlm.nih.gov/32511619/
Others have told me models calc'g 5-12 median 8 or 9.
Asymptomatic and superspread makes it difficult.
Others have told me models calc'g 5-12 median 8 or 9.
Asymptomatic and superspread makes it difficult.
Commentators have noted that R0 values are behaviour dependent. Part of the R0 is how transmissible the virus is in our situation. So, when the very way we live changes, our transmission patterns change, and R0 values would change. https://twitter.com/jmcrookston/status/1287467551061090306
SARS2.
R0 2.5-3.5?
Right.
R0 2.5-3.5?
Right.
SARS. Metropole Hotel.
Index case thought to have thrown up on the floor.
All grey units had people who got infected.
Index case thought to have thrown up on the floor.
All grey units had people who got infected.
In Canada, SARS spread through an ER including 7 people who just happened to be there.
Note last line, HCW who used droplet precautions still got sick.
Note last line, HCW who used droplet precautions still got sick.
SARS again. Hospital. Air distribution predictions matched actual attack. https://twitter.com/jmcrookston/status/1289218381032243200
MERS. 2016.
Hospital.
Coloured dots infected. Red is index.
This thread has all the other pictures but airflow through open windows matched the infection pattern.
https://twitter.com/jmcrookston/status/1289252870735331330
Hospital.
Coloured dots infected. Red is index.
This thread has all the other pictures but airflow through open windows matched the infection pattern.
https://twitter.com/jmcrookston/status/1289252870735331330
Finally the maitre of contact transmission, Chapin himself, in 1910, said measles was airborne _at least within doors_ and that it would not be air-borne further than between adjacent beds.
Finally, Chapin himself said while he believed pathogens were not significantly transmitted through the air, he himself said further investiation needed to be undertaking to make sure he was right.
"We must be on our guard lest our generalization carry us too far"
"We must be on our guard lest our generalization carry us too far"
NB From 2016 Hui Rossi and Johnston (eds.) "SARS, MERS, and other viral lung infections."
Note "mode"
Note "mode"
Found this article from 1938 stating that measles is transmitted by "droplet".
As noted in this thread, we now accept it's airborne/aerosol (not just droplet and further than 2m).
As noted in this thread, we now accept it's airborne/aerosol (not just droplet and further than 2m).
To finish this thought: so we used to think measles was "droplet" until later, big outbreaks over distances and in offices made it no longer possibly for droplet people to deny aerosol, so we accepted. Elsewhere noted this for TB, etc.
To keep everything together, I got into a side discussion about the R0 for SARS-CoV2 here (off this measles thread) and because I mentioned some study names, I'll link here: https://twitter.com/jmcrookston/status/1308343188520865792
Yet another estimate of the R0 of measles, all pre-vaccination, here.
https://twitter.com/jmcrookston/status/1309915342777520135
Not as high as 12-18, as this whole thread noted.
https://twitter.com/jmcrookston/status/1309915342777520135
Not as high as 12-18, as this whole thread noted.
I talked about MERS in this thread, so I'll add this link to a short thread I had lost that talks about a 2016 article discussing finding MERS in the air at a hospital: https://twitter.com/jmcrookston/status/1306394522860089348
Adding to this measles thread:
This is Ehresman 1994. https://pubmed.ncbi.nlm.nih.gov/7876616/
12 year old boy with measles led to 25 more cases over 3 generations.
He was thought to have directly infected 5 at track and field event, 8 at opening ceremonies and 3 first aid volunteers.
This is Ehresman 1994. https://pubmed.ncbi.nlm.nih.gov/7876616/
12 year old boy with measles led to 25 more cases over 3 generations.
He was thought to have directly infected 5 at track and field event, 8 at opening ceremonies and 3 first aid volunteers.
What is interesting is that 2 of the 8 at the opening ceremony were sitting 30m up on the second floor of the stadium, near an air vent which vented air taken from ground floor.
The only problem is, it's the _only_ report I can find with this kind of long-range transmission in years of reports.
Further, Skagit choir (SARS2) was 1 person to 50 or 60 in ONE generation. This is 1 to 26 in 3.
So there isn't this magic line between "airborne" and not.
Further, Skagit choir (SARS2) was 1 person to 50 or 60 in ONE generation. This is 1 to 26 in 3.
So there isn't this magic line between "airborne" and not.
Comments about ventilation. Refers to Riley for some description of other measles in air vents - so that would be a second report. I'll pull when I can.
Riley was pro-diseases spreading by aerosol etc.
So this is a little awkward. But not for me.
Riley was pro-diseases spreading by aerosol etc.
So this is a little awkward. But not for me.
Riley worked under Wells.
Wells & Wells (his wife) studied aerosol spread, that you could aerosolize bacteria up to the second floor of Harvard, and UV slashed measles rates in schools. Posted elsewhere, or perhaps in this thread even.
Wells & Wells (his wife) studied aerosol spread, that you could aerosolize bacteria up to the second floor of Harvard, and UV slashed measles rates in schools. Posted elsewhere, or perhaps in this thread even.
Before that Chapin, proponent of close contact explained by droplet, even himself knew scarlet fever (a bacteria - bigger than virus) could occasionally get to the second floor. I posted that too.
The second figure from the article.
Jumping back to Bloch. Infected was in the office one hour, infected others, including some after he left.
NOTED: That the authors said airborne spread of MEASLES was RARE. Last line.
And we are still debating with certain people that COVID-19 is airborne. Honestly.
NOTED: That the authors said airborne spread of MEASLES was RARE. Last line.
And we are still debating with certain people that COVID-19 is airborne. Honestly.
Back to Remington:
Infected was emitting 144 quanta of infection/min. were infected after he left the premises
NOTE: Airborne infection may happen more often than we think, so we should adjust.
And we are still debating with certain people that SARS-CoV-2 is airborne? Honestly
Infected was emitting 144 quanta of infection/min. were infected after he left the premises
NOTE: Airborne infection may happen more often than we think, so we should adjust.
And we are still debating with certain people that SARS-CoV-2 is airborne? Honestly
For Skagit choir event, infected estimated as emitting 1000 quanta per hour (= 16 quanta/min) of SARS-CoV-2
https://www.medrxiv.org/content/10.1101/2020.06.15.20132027v2
cc authors: @jljcolorado @kprather88 @ShellyMBoulder @CathNoakes @linseymarr (to note measles quanta in my previous post)
https://www.medrxiv.org/content/10.1101/2020.06.15.20132027v2
cc authors: @jljcolorado @kprather88 @ShellyMBoulder @CathNoakes @linseymarr (to note measles quanta in my previous post)
And hey while we're looking at old measles arguments, put on your legwarmers let's visit 1989 to say hello to
**all the same arguments from 2020, hashed out 30 years ago**
Yup, measles had superspreaders & big infection events. Classic person-to-person couldn't account for it.
**all the same arguments from 2020, hashed out 30 years ago**
Yup, measles had superspreaders & big infection events. Classic person-to-person couldn't account for it.
1/2 This what was Chen said in that report.
It is, of course, basically _EXACTLY_ what people have been saying for all of 2020.
It is, of course, basically _EXACTLY_ what people have been saying for all of 2020.
2/2
- Chapin thought close contact.
- Wells showed could be in air.
- We eventually had situations of measles spread that could not be explained by close contact.
Le Fin.
So let's Le Fin on SARS-CoV-2 already. This is taking too long.
- Chapin thought close contact.
- Wells showed could be in air.
- We eventually had situations of measles spread that could not be explained by close contact.
Le Fin.
So let's Le Fin on SARS-CoV-2 already. This is taking too long.
Just linking to this other short post on measles R0s and attack rate. https://twitter.com/jmcrookston/status/1322626594087849984
