RALEIGH, N.C. — Schools are half-empty and doctors' offices are standing room only. These are some of the signs that the flu bug is in full swing in the Triangle.

At Partnership Elementary School in Raleigh, about half of the school is out sick.

"It hit hard this week for us," principal Judy Andersen said. "I have not actually seen the high numbers that we have out right now ever before."

Doctors who track the flu claim when so many students are out, flu season is at its peak. Even many of the students who came to school went home sick.

"A little extra rest and some medicine, I'm sure she'll be fine. It's just a cough, but I'm sure she'll be fine," parent Debbie Holoman said.

Officials say a big part of the problem is parents send their kids to school when they should not.

"They're supposed to stay home 24 hours after the fever breaks," Andersen said.

Wake County Human Services sent letters home reminding parents that children should stay home if their fever is 100 degrees or higher, they are vomiting or have a severe headache.

"The symptoms really match classic influenza," said Dr. Thomas Flaherty, of Rex Pediatrics in Cary.

Many of the kids who are not in class are at the pediatrician's office. Flaherty said keeping kids at home helps, but even that cannot stop the spread.

"They can be infectious anywhere from 24 to 48 hours before you actually see any symptoms," he said.

Doctors say it usually takes about two weeks for the flu to run its course. Until the desks are full, teachers plan on teaching the same lessons over and over again.

"Next week is going to be a little bit of review and catch up so that everybody will be on a level playing field," Andersen said.