Crappy couple of days

The last couple of days I have been really run down. Tuesday morning I woke up with a slight fever, chills, headache, nausea and dizziness. Sounds fun, eh? Same deal today. So it's been no work (and no running) for me for the last couple days.
One thing I really don't like about my job in the number of people I come into contact with in a given week. On average, I see about 70 students and some of them more than once per week. All my classes are given in small rooms (because we have small groups) so there's no escaping the sickies. I kinda wish people would stay home a little more often rather than infect all the people around them. Most of my students work in an office at a computer, so I guess for them they can suffer through - they can feel miserable at their desk, hack all over the keyboard and no one is worse off. Sadly, that doesn't work for me when I'm at the front of the class. I have to be on all the time, especially with adults. If I don't feel I can give at least 75%, I stay home because I'm doing no one any good at that point. Ideally, I'd just not get sick in the first place but that doesn't seem to be working.