How can CDC find Anthrax spores?

Is it pure luck where they take a swab test?

Not sure what you’re getting at. You mean, how do they decide where to swab you? I’m not sure why they’re swabbing nasal cavities, but probably because that’s the spot that’s been proven in the past to contain spores.

You mean, how do they decide which offices and people to check? I guess just wherever they think the spores might have drifted, or been carried along on air currents or people’s clothing and hair.

Duck, The later of your statements. In offices.

I’ve wanted to know this too. Question refers to offices, buildings, etc.
From what I’ve heard, the spores tend to hang around in one part of the air for quite a while. So when the go into a building, do they take air samples from the top, bottom, left, right, front, back, and center of every room?
Even if they do, that leaves a lot of space unchecked. Maybe they check every three feet? Man, that’s a lot of work!
Somehow, this topic always reminds me of Geiger counters. Radioactivity is a really simple thing to check for, because you don’t need to take a sample. The Geiger counter just tells you “Hey! You’re getting closer!” But something like anthrax, where ya gotta take samples, how do they do it?