Minnesota is experiencing the mildest flu season it's had in recent years.
New data from the Minnesota Department of Health Thursday show 52 people have been hospitalized for lab-confirmed influenza since last fall, and three people have died. At this time last year, more than twice that number had been hospitalized, and there had been nine deaths.
Health officials also have seen fewer outbreaks of influenza-like illness in schools and nursing homes: two outbreaks occurred in long-term care facilities and 16 outbreaks were reported in schools. Last flu season there were 215 school outbreaks and 54 nursing home outbreaks.
Some speculate that the mild winter might have something to do with the mild flu season, but health officials said it's probably not that simple.
Temperature differences aren't enough to explain why a flu season is quiet or active, said Kris Ehresmann, who directs the health department's Infectious Disease Epidemiology, Prevention and Control Division.
"It's important to keep in mind that flu season in the Northern Hemisphere is the same months whether you're in Florida or whether you're in Minnesota, and so even though ours has been pretty mild, their weather has been that much better and they will still see cases of influenza," she said.
Increased flu activity has been associated with a lack of humidity, Ehresmann said. Another factor — one that wouldn't be easy to measure — is how much people are congregating indoors, which increases the virus's ability to spread, she said.
But Ehresmann said the flu virus is extremely unpredictable, and health officials usually don't know what to expect from year to year. It's possible flu activity will pick up before the season ends in April, health officials said.
While the uneventful flu season is good news, Ehresmann said it might not bode well for the next flu vaccine campaign.
"When you have a quiet season like this it is really easy for the public to become complacent," she said. "Well, next year we don't know, it could be a really crazy flu season and now the public is thinking, it wasn't bad last year I won't take advantage of a flu shot. So it really makes it hard to remind people of the value of vaccination."
Health officials won't know until next year what percentage of Minnesotans got flu shots. Last season, an estimated 46 percent of Minnesota adults were vaccinated against the flu, according to numbers released Thursday by the Centers for Disease Control and Prevention.