Minnesota health officials said Tuesday that many more schools are reporting influenza outbreaks, a day after hundreds of students in the Shakopee district called in sick with the flu or flu-like illnesses.
More than 300 students at Shakopee's West Middle School were absent with flu-related illnesses or flu symptoms — about 28% of the student body, according to a notice posted on the district's website. Another 100 students were out with flu-related illnesses at Sun Path Elementary, which has a total enrollment of 593.
Also Tuesday, school officials announced that a boys' basketball game between Chanhassen and Buffalo high schools scheduled for Tuesday night was postponed due to the high level of illness reported at Chanhassen High School.
School districts are required to contact the Minnesota Department of Health when at least 5% of the student body is absent and reporting flu and flu-like symptoms, but many schools are reporting absentee rates between 10% and 20%, said Kris Ehresmann, the department's infectious disease director.
The state has already reported 55 school-related outbreaks so far this season, including 13 in the first week of December, but Ehresmann said that number will be "up significantly" when the state releases the latest weekly flu numbers on Thursday. The state also has reported 176 flu-related hospitalizations, and Ehresmann said a higher-than-usual percentage involve children.
This year's influenza season so far has been unusual in that a B strain of the virus is circulating broadly; usually A strains of the virus are more common at this time of year, and B strains emerge only later in the winter.
B strains historically have spread more among children, so Ehresmann said the current uptick in school-related outbreaks was predictable. However, she stressed that B strains of influenza are common and addressed by the flu vaccine, which remains widely available.
"It's the same contagiousness," she said. "It's the same symptoms. It's the same thing. It's just that it's a different type."
Flu symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache and chills, the Health Department said.
"Everyone 6 months of age and older should get a flu vaccine each year," the department said on its Facebook page. "Flu activity is picking up in Minnesota. It's not too late to get vaccinated."