INDIANAPOLIS (AP) â€” Indiana, like most states, is in the midst of one of its worst flu seasons in recent years, and health officials said Friday that it's too early to tell whether the season has peaked.
The season's 40 flu deaths make it Indiana's deadliest in five years, and with several months of cold weather still in store, that figure is almost certain to rise. Flu season typically runs from October through mid-May.
Last flu season, only three Indiana residents died of the disease. In the flu season that ended in spring 2008, however, 73 people died, and four seasons before that, there were 91 Indiana flu deaths.
Flu virus strains change every year, making it difficult to predict how severe each new season will be and accounting for the big swings in the death count, said Pam Pontones, an epidemiologist for the state health department.
"What we really have to do is work very diligently to conduct surveillance ... to monitor influenza activity and look for signs that the virus may be changing or if there is a particular virus that appears to dominate," she said.
This year, the H3N2 strain seems most prevalent, and it's a strain that the flu vaccine protects against.
Those 65 and older are the most vulnerable to suffering severe consequences as a result of the flu, particularly those who live in long-term care facilities, where the disease easily spreads. In Indiana this flu season, 33 of the 40 people who died were 65 or older and all but two of the 40 had a pre-existing medical condition such as heart disease, diabetes, asthma or a renal disease.
"As age goes up, immunity drops," said Arif Nazir, a geriatrician at the Indiana University School of Medicine. "As we age, we sometimes have diseases that lead to decreased ability to fight against infections. ... Our immunity is weaker."
Symptoms typically include fever, cough, runny nose, head and body aches and fatigue. Some people also have vomiting and diarrhea, and some develop pneumonia or other severe complications.
Older people also recover more slowly.
"Once a crisis like a flu-like illness hits, they run out of their energy quickly, which makes them weak and appear to be sicker than other people," Nazir said.
Some residents of long-term care facilities can also be reluctant to get the vaccine, Nazir said. But it could be the difference between life and death. Vaccines are about 65 percent effective at preventing the flu, and they also lessen the severity of symptoms for those who still end up getting sick.