It's not the common cold.
The flu this year has been sending people across the suburbs to intensive care units, and some have even died.
How can you avoid the flu?Ÿ Get a shot. Health officials say vaccination is the best way to prevent flu.
Ÿ Wash your hands.
Ÿ Sneeze into your elbow, not your hands.
Ÿ Don't touch your eyes and mouth.
Ÿ Stay away from people with the flu.
Ÿ If you get sick, stay home from work or school.
And officials say that while flu can be dangerous every year, people still don't treat the disease with the respect it deserves.
"I've seen some very sick adults," Dr. Caroline Wolf of the DuPage Medical Group in Glen Ellyn said of patients she has seen this flu season. "Sicker than they ever thought they would be."
As the number of people hospitalized with the flu rises, health officials and doctors are begging people to get preventive flu shots. The chief flu strain this year is H1N1, the same one that caused increased attention to the disease in 2009. It is known for striking young adults who otherwise are healthy, unlike other flu types that mostly target the young and elderly.
In the suburbs, the flu is spreading. There have been 44 intensive care admissions in suburban Cook County, 53 in McHenry County, 13 in Lake County, nine in DuPage County and five in Kane County, officials said Thursday. Six deaths were reported in suburban Cook County, and one death was reported in DuPage County.
In last year's flu season, 817 people were admitted to intensive care units and 135 died statewide, according to the Illinois Department of Public Health.
Not every case is so severe, but flu still can cause serious problems.
"I think there is a lot of misunderstanding out there about what influenza is," Wolf said.
She said influenza is not a cold that lets you go to work and recover quickly. It is the type of thing makes you sick for a week -- lying-on-the-ground sick.
And some officials believe it's only just begun.
Dr. Terry Mason, the Cook County Department of Public Health's chief operating officer, said he does not believe the flu season is near its end.
"The activity hasn't even peaked yet," Mason said in a statement. "We expect more ICU admissions and potentially deaths in the coming weeks."
DuPage County Health Department officials say they're seeing increases in flu cases at all levels of the health care spectrum, including inpatient and outpatient cases, visits to the emergency room and over-the-counter drug sales.
Lake County Health Department spokeswoman Leslie Piotrowski says she's seen the same thing.
"Local pharmacies are noting an overall increase in the use of common cough and cold medications, and visits to health care providers for flu-like symptoms have also increased over the past few weeks," Piotrowski said Thursday.
Lake County health officials issued flu-prevention tips, saying a vaccination is the best way to prevent getting influenza, but risks can be reduced by washing hands regularly with soap and water or, if need be, an alcohol-based hand rub.
In addition, cough into your elbow instead of hands and avoid touching your eyes, nose or mouth because germs are spread that way. Also avoid close contact with sick people.
The Kane County Health Department performed surveillance at a St. Charles nursing home that reported an outbreak on Dec. 27, according to Kate Marishta, assistant director of disease prevention. Surveillance included isolating the infected patient, ensuring all the staff members are vaccinated and testing people who show symptoms.
"We watch those clusters from the beginning because we don't want the outbreak to spread farther," she said.
In McHenry County, there are no reported cases of H1N1 thus far in 2014 and no flu-related deaths, said Deborah Quackenbush, public information officer for the McHenry County Health Department. She said the department is preparing for more cases in the coming weeks.
While the H1N1 strain is part of this year's flu vaccine, McHenry County ran out of its supply of more than 1,000 doses two weeks before Thanksgiving. As a result, the county will not hold any flu vaccination clinics or other related events.
McHenry residents should instead obtain the shot through their physician or a local pharmacy.
"We want to make sure we get the word out that this particular strain can really impact everybody, not just older adults," Quackenbush said. "So please get your flu shot."
• Daily Herald staff writers Lenore Adkins, Jamie Sotonoff, and Bob Susnjara contributed to this story.
Flu: Health department monitored one St. Charles nursing home