Back to school season this year includes a new twist: Planning for a swine flu breakout.
The government released Friday new guidance for educators and public health officials, aimed at containing outbreaks while avoiding keeping kids out of school any longer than necessary.
Schools should only close if large numbers of students come down with swine flu, officials said.
Sick kids could return to class 24 hours after a fever is gone, a change from recommendations that people with swine flu stay home for a week.
Final decisions on school closings rest with local officials. But they look to the guidance coming from the Centers for Disease Control and Prevention, the U.S. Department of Education and related state agencies.
No one is eager to repeat the confusion that followed the virus outbreak last spring, when more than 700 schools in half the states temporarily closed their doors, several in Hillsborough County.
At the time, school officials were acting on the CDC's advice, which changed as it became clear the virus was milder than initially feared.
Hillsborough educators know that parents will have questions.
"Under what circumstances would you close a school? What do we need to do? And please assure us if kids are sick, you'll send them home," said Stephen Hegarty, spokesman for Hillsborough schools, ticking off a few on his mind. Officials will try to have as many answers as possible before classes resume at the end of the month, he said.
But swine flu remains an evolving public health threat. The government's latest guidance reflects uncertainty over what may happen in the fall.
"Basically, this will be a tiered response. If there's a handful of children at a school who might be sick, we want the parents to keep them home. If the numbers escalate dramatically, then we might have to close the schools," Education Secretary Arne Duncan said.
Like their Hillsborough counterparts, Pinellas officials are planning for the flu.
"Communication with parents and employees about taking precautions to protect themselves and children to reduce the spread of the flu has begun as we approach the start of a new school year and will continue on a regular basis," said Pinellas schools spokeswoman Andrea Zahn in an e-mail.
Unlike regular seasonal flu, this virus has not retreated during summer and so far has infected more than 1 million Americans.
Information from the Associated Press was used in this report.