More cases, deaths in other states

The Oklahoma Department of Health said Thursday the state has had eight influenza-linked deaths since September 30.

Additionally, the Minnesota Department of Health has counted 27 flu-related deaths. "We are clearly at a high level of influenza activity in the state," Minnesota Health Commissioner Dr. Edward Ehlinger said in a statement. "But it's important to keep this year in perspective: What is occurring has happened before."

Pennsylvania has had 22 flu-related deaths so far this season, according to data from the state's Department of Health. Most of these deaths occurred among people older than 65, but the fatalities included two individuals younger than 50 who were otherwise healthy.

Lehigh Valley Hospital-Cedar Crest in Allentown, Pennsylvania, set up a heated tent outside the hospital to serve as a clinic. Anyone with mild flu symptoms can be treated quickly and discharged, isolated from more serious cases. The hospital has been seeing an additional 80 to 100 patients with flu-like symptoms daily, officials told CNN affiliate WPVI.

Indiana has seen 13 confirmed adult flu-related deaths since November 1, and two pediatric deaths, according to the state's health department.

Arkansas has seven confirmed flu fatalities. Many of the hospitals are at capacity because of the flu or other illnesses, state health spokesman Ed Barham said.

South Carolina has counted 22 flu-related deaths this season, compared with one for all of 2011, according to the South Carolina Department of Health. From September 30 through January 5, the state saw 1,084 influenza-related hospitalizations, the department said.

In Illinois, Department of Public Health Director Dr. LaMar Hasbrouck said Wednesday that since October, six flu-related deaths of patients in intensive-care units have occurred.

"We have been and continue to see an increase in flu activity across the state. The flu strain that is predominately circulating this year is typically more severe, with more hospitalizations and deaths," Hasbrouck said. "From the beginning of October through the end of December we've seen almost 150 people admitted to hospital intensive care units with influenza like illness.

"This compares to last year at this time when there were only two ICU hospitalizations and no deaths."

In Michigan, there have been four pediatric deaths related to the flu, said Angela Minicuci, public information officer for the Michigan Department of Community Health.

And the North Dakota Department of Health is reporting 1,077 cases of flu in the state as of Wednesday -- a sharp increase from the 625 cases reported last week.

Dr. David Zich, internal medicine and emergency medicine physician at Northwestern Memorial Hospital in Chicago, said this is the worst flu season he's seen in his 12 years at his hospital, in terms of the concentration of patients.

Northwestern Memorial Hospital is on "bypass," which happens when it is beyond capacity because of an influx of patients, such as during flu season.

That means advanced-life support ambulances with patients who are stable are referred to the next closest hospital, no more than five minutes away, Zich said, and transfers are not accepted from outside hospitals. For everyone else, they are open for business.

"The majority of flu patients are sent home, with very little else done, so we can handle that," he said.

Why so many cases?

Zich theorizes that one reason there are so many flu cases is that the heart of the flu season coincided with the December holiday season, meaning many people were already sleep-deprived from parties and were more likely to get sick.

Those who went to gatherings of family or friends may have already begun to feel sick, and spread the virus to others. People are generally contagious the day before symptoms start, and for five days after becoming sick, according to the Centers for Disease Control and Prevention.