MADISON (WKOW) -- From October 1, 2020 to October 2, 2021, Wisconsin recorded just 100 confirmed cases of influenza. That was down from the 36,175 cases the state saw during the 2019-20 flu season.
"This was shockingly abnormal," Dr. James Conway, a pediatric infectious disease specialist with UW Health, said. "I've been doing this a long time. I've never been through a flu season like that. It was really unprecedented."
But total flu cases weren't the only category that saw a major decline. Hospitalizations from influenza in Wisconsin dropped from 4,425 in the 2019-20 season to 22 in the 2020-21 season.
There were also no flu deaths in the state.
"We are referring to it as a season that never happened," Thomas Haupt, the influenza surveillance coordinator for Wisconsin's Department of Health Services, said. "We're glad that it didn't happen, but we're hoping it doesn't come back with a vengeance as a result."
Haupt said he meets monthly with other influenza coordinators and the Centers for Disease Control and Prevention, and every state had an unusually inactive flu season.
"Nobody has been seeing anything at all," he said. "So, as a result, we can't even tell you what the predominant strain was this past year."
Conway said that made it more difficult for scientists to develop this year's flu shot. He said researchers typically look at data from the most common strains to determine which flu strains will likely be active the next year.
"For this year's flu vaccine, it was basically just making a good guess, and it ended up being, essentially, using the same strains that were in the 2019 vaccine," he said.
Even with the guesswork, Haupt said he's confident the vaccine will be effective this year. However, he doesn't want people to rely exclusively on it.
He said other virus prevention measures, like hand washing, wearing a mask and staying home if you're sick will slow the flu's spread.
Conway said he's hopeful the experiences people had during the pandemic will change how they approach staying healthy during flu season.
"If people are sick, they need to stay home," he said. "This old practice of toughing it out and figuring out a way to make it work and going to work sick because we're tough and we're gonna get through this or sending your kid to school because they've still got a little bit of a snotty nose, that's just no longer acceptable."
Conway and Haupt said while they anticipate more flu cases this year than last, they're hoping numbers won't reach the same level they did during the 2019-20 season.
Conway said a large surge in flu cases on top of COVID-19 hospitalizations would put an immense strain on health care workers.
"Hospitals are pretty stretched," he said. "If we add in a flu surge at any point, we could see significant capacity challenges in the hospitals and in the clinics that manage patients with respiratory illnesses."