How could coronavirus spread through ventilation in Adelaide’s hotel quarantine set-up?

As authorities in some states declare coronavirus to have been “virtually eliminated”, control efforts have switched focus to bolstering one of the remaining frontlines: hotel quarantine.

In recent days, both South Australia and Victoria have begun looking into improving ventilation after recent cases — including a cluster that forced SA into lockdown — were linked to medi-hotels.

Here’s a breakdown of what authorities believe happened in Adelaide.

How did it spread via ventilation?

Airflow inside buildings had not always received as much attention as other risk factors, such as uncovered coughing and sneezing.

But that’s now changed in South Australia, after health…