Should I notify students that I've interacted with after getting sick, by email?

Either you infected them, or you didn't. Sending an e-mail about it will not change that (enough time has passed that telling them to wash their hands now will make no difference).

Therefore, it only makes sense to send an e-mail if it turns out to be something where early treatment can make a big difference, or where ignoring it can do harm. (IIRC, this year's flu is an especially bad one, and students might be tempted to dismiss it as just a cold. It's good to remind people that the flu kills and that they need someone to check in on them every few hours.)

Technically, an early warning might also let them avoid people until they are sure they aren't infectious, but in practice that is unlikely to happen as "I was in the same room as someone with fever earlier" probably won't be accepted as a valid reason to skip class...

I would send out an email, but I would recommend caution and measure in writing it, so as not to cause undue panic.

Mention exactly what happened, along the lines of what you wrote here. Just state facts, and urge that anybody who starts developing symptoms to seek medical attention.

I should mention that I am one of the "immunocompromised" people mentioned in the other answers. Since full lecture notes were posted online for each lecture, I asked students who were contagious with something to please exercise caution, because I really couldn't afford to get sick.

If it turns out to be something serious that requires treatment, yes. Also, if it's the flu, yes. But if it's a garden variety virus, no. There are so many bugs on campus, students are exposed quite often, and your bug is just one among many.

However, if you shook hands with someone, or sneezed on someone, then notify the individual.