[ceejayoz]

> I doubt the data supports this mindset

Doubt all you like, it's a thing. "In the United States, the Centers for Disease Control and Prevention estimated that roughly 1.7 million healthcare-associated infections, from all types of microorganisms, including bacteria and fungi combined, cause or contribute to 99,000 deaths each year."

ERs are dirty, busy places filled with pathogens. It's not uncommon to share the waiting room or a semi-private room with other patients with unknown conditions throwing up or coughing, with the resulting droplets/areosols in the shared air. Even before COVID, going to one when it's a borderline situation requires a bit of calculus, especially if you're medically complex.

https://en.wikipedia.org/wiki/Hospital-acquired_infection

> unless there’s some specific pre-existing issue

That'd be the 26 weeker thing I mentioned, yes.