The worst may be over.
As of Jan. 12, leading indicators of flu activity in Chicago had dropped to early December levels, according to the latest data from the city Health Department, released Friday. However, the numbers remain significantly higher than they were at this point in previous flu seasons since the swine flu pandemic in 2009.
"The peak of activity is over, but we still have a lot of disease," said Dr. Julie Morita, the department's medical director.
It's a similar story on the state level, where flu-related hospitalizations for the week ending Jan. 12 were the lowest in four weeks.
"Clearly we're having a decline," said Dr. David Zich, an internal and emergency medicine physician at Northwestern Memorial Hospital. He said the hospital is dealing with half the flu-related volume it had three weeks ago.
On Friday, the flu season entered its second week at epidemic levels nationwide, meaning more than 7.2 percent of all deaths are linked with influenza and pneumonia.
As of Jan. 12, the federal Centers for Disease Control and Prevention found 48 states with "widespread" flu activity, including Illinois. Forty-seven states earned the CDC classification a week earlier.
In a conference call Friday, CDC Director Dr. Thomas Frieden declined to say whether the flu season has peaked nationally.
"You can't predict the future with flu," he said. "Remember, even when you're halfway through the season, that means you've still got half of the season left."
Frieden called the flu season "worse than average," with a particularly devastating impact on the elderly. Nearly half of all flu-related hospitalizations since Oct. 1 were for people 65 and older, according to the CDC.
In Chicago, almost three-quarters of this season's hospital visits due to flu-like symptoms have been among people 50 and older. Morita said this season's dominant strain — H3N2 — tends to affect young and old people more than other variations.
Health officials also have blamed H3N2 for the flu season's early start. It kicked off a month sooner than usual, Frieden told reporters.
Zich attributed the early spike to a "perfect storm of people who were very run down" during the holiday season. Because the flu season picked up in early December, he explained, more contagious people got together around Christmas than in previous years.
"This is not a supervirus," Zich said. "It's just bad timing."
Morita said Chicago's supply of flu vaccine is holding up well. She recommended that people still get vaccinated.
"We still need to keep our guard up," she said. "Our flu season is not over."Copyright © 2015, The Baltimore Sun