Hundreds of students called in sick this week at Clayton Valley Charter High School in Concord, and school officials on Thursday were scrambling to head off what they believe is an outbreak of the flu.
Crews at the school are busy cleaning and disinfecting surfaces to try to stop the contagious illness from spreading.
"We disinfected the bathrooms again yesterday; we wiped down desktops with disinfectant wipes," school Operations Director Alison Bacigalubo said.
Parents received a notification letter saying the illness should last only a few days, and school officials said attendance is already staring to creep back to normal numbers.
Student Annjali Bali, 14, was seen leaving the campus early Thursday after experiencing symptoms.
"My sore throat, really runny nose and fever," Annjali said, carrying a sick note.
Annjali’s father, Lokesh, said he received a text from his daughter indicating she didn't feel well. He was one of hundreds of Clayton Valley Charter parents who kept their kids home from school this week.
Each day this week, about 250 kids stayed home, about double the absentees on a typical day, school officials said.
Bacigalubo said other schools in Contra Costa County also are dealing with outbreaks.
"Last week, De La Salle had a few incidences; I think Antioch and Pittsburgh had issues over there," she said. "This week it happens to be our week of influenza."
Some students staying home sick say they now have more time to cram for a couple of big tests.
"Some teachers didn’t take tests because of all the absences," Annjali said.
And while sick students rest up, many of their parents will be taking some extra precuations to keep themselves off the sick list.
"Everyone has to just keep washing their hands," parent Cindy McIntyre said.
The county health department has not seen a spike in flu reports this season and confirmed cases typically only happen when someone is hospitalized.