Charleroi Area School District in Pennsylvania returns to remote learning after 80 students came to the nurse's office during a winter flu outbreak

A Pittsburgh-area school district returned to remote learning after nearly 100 students experienced flu-like symptoms during one of the worst flu seasons in the past decade.

Classes at Charleroi Area School District elementary, middle and high school campuses have been moved online after dozens of elementary school students became ill.

Officials said 81 students went to the nurse's office on Wednesday and reported flu-like symptoms. More than thirty students were sent home, some of whom had to be hospitalized. That prompted officials to close the district's schools and move classrooms online.

“But we know this was the right choice to protect our students and our staff,” Charleroi Superintendent Ed Zelich told CBS.

The decision in Pennsylvania follows outbreaks in schools and districts across the country, including in Texas, Tennessee and Michigan. In some areas, up to 40 percent of students report illness-related absences in a single day.

Superintendent Ed Zelich called the decision to go online “the right thing to do to protect our students and staff.”

Although in-person learning resumed Monday, the district was still plagued by high absenteeism rates, with 36 percent of students not attending school

In Charleroi, primary, middle and high schools were closed until Monday, while all weekend activities were cancelled.

Several staff members, including cooks and custodians, went home with the same symptoms.

Zelich said the outbreak was unprecedented in his 10-year tenure with the district.

“The turning point was when the primary school nurse called me yesterday and said she needed to see me immediately,” the superintendent said Thursday.

'If you have 80 students in the office and more than 30 of them go home before noon, we have a problem.'

The district shifted to remote learning using systems put in place during the COVID-19 pandemic.

Although in-person learning resumed Monday, the district was still plagued by high absenteeism rates, especially among younger children. At least 30 elementary school students were sent home, and 36 percent of district students were absent.

The district does not plan to return to virtual learning this week, but Zelich encouraged parents to exercise caution when deciding to send their children to school.

Pennsylvania's school district isn't the first to experience a massive outbreak, with schools in Texas, Tennessee and Michigan closing classes completely. Pictured: Charleroi Middle School in Pennsylvania

According to the CDC, more than a dozen states are experiencing increases in infections from influenza, respiratory syncytial virus and COVID (Photo: COVID-19 under a microscope)

Flu viruses are constantly adapting, producing new strains every year that are immune to existing vaccines. The infection rate is highest among children

Illnesses have hit schools across the country, and last week the Happy Independent School District in Texas canceled school after about 40 percent of its elementary school students fell ill.

Chief Inspector Trevor Egdemon said the district was running out of teachers because so many were absent, ABC7 reported.

On December 7, Perry County Schools in Middle Tennessee announced it would be closed for the rest of the week due to an unspecified “illness.”

This week, Michigan's Buckley Community Schools canceled school districtwide after about 30 percent of students became ill.

Superintendent Jessica Harrand explained WPBN that most students were primary school students and most showed flu-like symptoms.

More than a dozen states are experiencing increases in infections from influenza, respiratory syncytial virus and COVID, with infection rates being “high” or “very high.”

Centers for Disease Control and Prevention reports that 15 states are experiencing increased infection rates.

The figure is based on the weekly percentage of visits to healthcare providers or hospitals in which patients complain of fever, cough or sore throat.

According to data from the CDC, the 2022-2023 flu season is one of the worst in the past decade, with 31,000,000 symptomatic cases reported to date.

Flu viruses are constantly adapting, producing new strains every year that are immune to existing vaccines. This allows the disease to spread widely, with particular consequences for children, whose underdeveloped immune systems put them at greater risk.

The World Health Organization estimates about one billion cases of seasonal flu each year, including three to five million cases of serious illness.

The virus causes between 290,000 and 650,000 respiratory deaths each year around the world.