Thread by @jmcrookston

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.

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?

cc @kprather88 @jljcolorado @linseymarr

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.

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.

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.

First article is Bloch: pubmed.ncbi.nlm.nih.gov/3982900/

Second article is Remington:
pubmed.ncbi.nlm.nih.gov/3974036/

Third article, from 1935, is titled as below.

Link: jstor.org/stable/224834?…

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.

2. measles R0 (Reff) varies widely. The shaded area is the often cited 12-18. (Guerra 2017 thelancet.com/journals/lanin…)

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").

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. 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. " 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.

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.

SARS. Metropole Hotel.

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.

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

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"

NB From 2016 Hui Rossi and Johnston (eds.) "SARS, MERS, and other viral lung infections."

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).

journals.sagepub.com/doi/pdf/10.117…