Illinois is currently experiencing one of its worst influenza seasons in recent memory.
Illinois is one of 41 states that is experiencing widespread influenza activity, and in the U.S. flu activity has been higher than the national average for four consecutive weeks, according to the Center for Disease Control and Prevention.
Illinois has not had widespread influenza activity this early since the 2003 flu season, with the exception of the H1N1 virus in 2009.
From December 16 to December 22, Illinois recorded 31 influenza related ICU admissions, three of which resulted in deaths.
“We've had a dramatic increase [of flu cases] in the last few weeks,” said Melaney Arnold, a spokeswoman for the Illinois Department of Public Health. “There has been early December activity.”
It's difficult to pinpoint the cause for the uptick in flu cases, Arnold said.
“The flu is very unpredictable,” she said. “It could be due to holiday gatherings and people getting together, but there's no way of knowing.”
Nationally, the percentage of people visiting their health care provider with influenza-like illness (ILI) is higher than normal, climbing from 2.8 to 5.6 percent in the last four weeks. Illinois is one of 29 states that is experiencing high levels of ILI, which is based on the percent of outpatient visits in a state due to ILI. Levels are measured from minimal to high, with high meaning ILI activity from outpatient clinics is happening much more frequently than normal.
Arnold said the typical peak for flu cases is in late January and early February, and the spike in December cases is unusual. If the trend continues and flu activity continues to increase throughout the winter months, Illinois could be in for one of its worst flu season in history.
“It's not too late to get an influenza vaccine,” Arnold said. “We've had a high number of cases, and we could still see more.”
Tracking influenza cases is done by measuring ICU patients who demonstrate flu symptoms. Doctors offices and health clinics also report patients who appear to be suffering from the flu, Arnold said.
“The only thing predictable abut the flu is its unpredictability,” said Tom Schlueter, Kane County Health Department public information officer. “We've had really low activity during the first six to seven weeks of the season. It's gone up really high in last few.”
One group of people possibly bucking the trend are school children. Students who have been out of school over the winter break are interacting less with other kids and are at a lower risk of getting the flu, Crystal Lake School District 155 spokesman Jeff Puma said.