Any programs to track illness in a school?

We had no strep in my school for over a month, I'd say. Then one preschool kid about three weeks ago came in. It's been really fascinating to see how it spread down the school floor he was on (first a case or two in the classroom across from his, then two doors down the hall, etc), and then, through sibling transmission, started on the floor above.

Does anyone know of an online program that could help me make a chart about when each student got sick and, maybe by color, keep track of sibling transmission? I think it would be very interesting to look at it like that, and maybe make a good posterboard presentation. We have no electronic health record program at my school, in case that matters (in case this kind of thing is standard on them. In fact, if it is, let me know so I can try to use that to make the case for EMR!)

Thanks!