They do not have specific guidelines. Schools are to work with the local health department.
They have said that if 2+ kids in one classroom test positive, the whole class will go home for 2 weeks. Single cases will be decided on a case-by-case basis of close contacts (per required seating charts). They also said that younger grades may have to send whole classes home because they realize the futility of seating charts for < 3rd grade.
That said - one positive kid in MS will likely mean 50-100 kids quarantined. We would hit 10-20% pretty quickly with that. The news today said that a local school started yesterday and sent home a kid mid-day who then tested positive.
We got additions to the already long FAQ for the HS and they are doing staggered passing periods, one way traffic in some areas, etc. I told a friend that every grade this year will be like the first month of kindergarten - where to line up, how to use the bathroom, how to walk in the halls, how to turn in homework.
Mama to three boys ('03, '05, '07)