Thread by @kevinpurcell

An interesting and carefully done piece of work on looking for SARS-CoV-2 in the air on a hospital patients room.

The found live virus, sequenced it and showed it was the same as the one the patient had.

There are a few caveats though. medrxiv.org/content/10.110…

This was done in a hospital room with at least 1 sick patient.

If the patient was emitting aerosols was that by normal respiration/speaking or by coughing?

Is the aersol from a resuspension of virus emitted as drops or droplets?

This is an n=1 study.

What was the viral load of the patient? They just report a positive PCR test not a Ct value.

Where was he emitting virus from? URT? LRT?

Is this typical of hospital patients (or any other patients)?

Live virus was found but at “small” (low? very low?) concentration in a hospital room that (aside from ICU) should be a “worst case” for finding virus.

What is the relative risk of aerosol transmission in normal environments by someone who is asymptomatic or paucisymptomatic compared to droplet transmission

This is the real question that impacts public health.

The broad epi evidence is against aerosols being a major xsmn risk

The last paragraph overstates their results (as people sometimes do at the end of the discussion).

“and can thus serve as a source for transmission of the virus in this setting.“

I’d replace “can” with “might” as they didn’t show this is infective for a person.