The number of reported flu cases has spiked in both Clark and Champaign counties so far this season, part of a statewide trend in which the number of influenza-associated hospitalizations has increased from four at this time last year to 169 so far in 2012.

Locally, 15 confirmed influenza-associated hospitalizations have been reported in Clark County, and another two are suspected, said Gabe Jones, an epidemiologist for the Clark County Combined Health District. Last year, there was only one confirmed case, which occurred in October.

In Champaign County, four hospitalizations associated with the flu this year have been reported, compared to none at the same time last year.

Local health officials said it’s difficult to say how the remainder of the flu season will play out but urged residents to get vaccinated. In Ohio, flu season can begin as early as October and stretch into March, so vaccinations will still be beneficial.

The flu season is different each year, and there’s no way to predict how mild or severe the rest of the flu season will be, said Shelia Hiddleson, director of the Champaign Health District. It’s also not clear why the number of flu-associated hospitalizations spiked this year.

“It could mean that we’re just doing a better job with surveillance, but it could also mean we’re seeing more cases early on,” Hiddleson said.

Plenty of flu vaccine is available in both Clark and Champaign counties, according to health officials. This year, the vaccine does cover the types of flu expected, Hiddleson said.

Local health departments only track cases in which an individual is hospitalized due to influenza, but Jones said the Springfield Regional Medical Center and Mercy Memorial Hospital in Urbana are also testing patients daily using rapid influenza diagnostic tests. As many as four to five patients a day are testing positive in Springfield and one to two a day are testing positive at Mercy Memorial Hospital.

At the Springfield Regional Medical Center, 181 patients have visited the hospital’s emergency room with flu-like symptoms, said Christa Tutwiler, a spokeswoman for Community Mercy Health Partners. Of those, 25 percent have tested positive for the flu. That is more than usual, Tutwiler said.

More than 3,300 residents in Clark County have received the flu vaccine at flu clinics and walk-in hours this year, Jones said.

In Champaign County, the health district distributed about 1,100 flu shots. That figure is lower than in previous years, Hiddleson said, but that is in part because pharmacies are also allowed to administer the shots, which was not the case in the past.

Along with the vaccine, residents can take some basic precautions to avoid getting the flu in the first place, said Dr. Bernadette deGuzman, a physician with South Burnett Family Practice. Residents should wash their hands regularly with soap and water, avoid touching their eyes, nose and mouth, get plenty of sleep and cover their nose and mouth with a disposable tissue when sneezing or coughing. If sick, they should stay home except to get medical care or for other necessities.

In addition to the flu, health officials also cautioned there appears to be an increase in norovirus cases in the region, a virus that causes inflammation of the stomach or intestines and can cause stomach pain, nausea and diarrhea. Some symptoms can be similar to the flu, Jones said. In the last two months there have been two confirmed cases of norovirus in Clark County and 17 outbreaks investigated statewide. The virus can be prevented by using proper hygiene, washing fruits and vegetables thoroughly, and avoiding preparing food for others when sick.