I recently took a 4 day vacation in Reno and Fallon NV and came back
with a sniffly respiratory infection which after 24 hours caused
development of a fever of 101 for a least part of a day.  There was a
lot of drainage from the nose and down the back of the throat, but my
nose never stopped up.  All symptoms were gone after 4 days. It came
on fast and left quickly.  OK, no big deal...

However, this thing turned out to be aggressively contagious - a real
mystery.  Nearly everyone I was with in any room caught it, and now it
is spreading rapidly.  No coughing nor sneezing required - just
sharing the air in a room is enough.  So now everyone in my office
caught it along with my mother and brother. With none of these people
was there any physical contact - hugging, etc. It's a public health
emergency microcosm.

I've been trying to search the Internet, but can't come up with
answers really.  It must be bacterial since it has a fairly short
duration.  Is this merely some type of flu?  Although I thought those
were always viral.  How often are respiratory infections so
_amazingly_ infectious?  If a significant number of people had this
thing, it would be impossible to have any public function, even riding
on public transit, etc.  I had no idea an airborne disease could be so
contagious.  It's the first illness of any kind I've had in at least a
decade.  I didn't catch it from anyone with whom I visited.  I asked
them all whether they had had any type of cold.  The answer was 100%
negatory.  So now at least a dozen people have what I brought back
from my vacation last week , and that will likely spread quickly to
their own people. I feel very guilty and curious.

Anyone have any ideas about this mystery?