DALLAS -- Schools across the country are fighting the flu, classroom by classroom. On Monday, Bishop Lynch High School resumed classes after it closed last week to let work crews disinfect the entire school property.
School nurse Patty Barton saw more kids in the clinic than in the classroom.
"This year it really is unprecedented," she said. "I probably saw about 30 kids here on Monday and sent 10 home."
Theand there are 39 states the U.S. Centers for Disease Control and Prevention says have especially high activity. With so many students and teachers getting sick, schools in at least 12 states have cancelled classes for a few days for cleanup and recovery.
The flu shut down classes Monday for the 815 students at Saint Thomas Aquinas in Dallas. More than 10 percent of the student body got sick.
"Even if we miss anything, the kids will have a chance to go home, get healthy and hopefully not bring that virus back to school," said Matthew Vereecke, the school's superintendent.
"It has been a tough influenza season so far this year," said Dr. Daniel Jernigan of the CDC.
He says the H3N2 strain of the flu is hitting patients over 65 very hard, but other strains of the flu are taking a toll on younger patients.
"Since the winter holidays, we've seen kids are really making up the predominant amount of influenza," said Jernigan. "They're taking that back to school, getting transmitted there. I think that's really what's driving a lot these visits to the outpatient clinic."