DAYTON, Ohio - The number of Ohioans hospitalized with the flu since last September jumped dramatically over the previous year, but health officials say there isn't an easy explanation for the increase.
Health officials say that 5,200 Ohioans were hospitalized with the flu from September last year through mid-May 18.
That's up from 595 hospitalizations during the 2011-12 flu season. It was also more than 2009-2010 when the swine flu pandemic led to 3,200 flu-related hospitalizations in the state.
Health officials said there is no indication that a new virus led to the spike in hospitalizations, The Dayton Daily News reported.
"There are lots of factors that come into play, and they're all independent of one another," said Dr. Thomas Herchline, medical director for Public Health in Dayton and Montgomery County. "There are years where there are more cases of people who get influenza but don't get that sick. And there are years were there are fewer cases, but more people go to the hospital."
The numbers did show that the flu season began about a month earlier than normal and hospitalizations started going up in mid-December.
Many of those hospitalized were 65 or older, which mirrored trends across the country.
The Centers for Disease Control and Prevention reported that seniors made up more than half of reported cases nationwide through the end of March.
People over 65 are generally more likely to be hospitalized with influenza because of weakened immune systems, said Brian Fowler, an epidemiologist with the Ohio health department.
Duane Stansbury, health commissioner in southwest Ohio's Warren County, said that the CDC found that this year's flu vaccine was less than 60 percent effective in healthy adults.
"A number of our cases were not directly related to a specific strain that was covered by the vaccine," Stansbury said.
"It's difficult to know if we had people who were not being vaccinated and getting sick or if we had people who were getting vaccinated and still getting sick and being hospitalized," he said.