Fewer cases of flu in S.D. this season

SIOUX FALLS — The flu season in South Dakota is running out of steam after sending fewer people to the doctor’s office or hospital this winter.

Ninety-one hospitalizations and three deaths were attributed to the flu through March 28, the most recent data available. There were 354 hosand 22 deaths in the 2008-09 flu season.

“Not only were there fewer confirmed cases but far fewer rapid antigen tests,” said Lon Kightlinger, epidemiologist in the state Health Department. “That indicates to me that far fewer people were sick enough to go to the doctor.”

Antigen tests are given in a doctor’s office and provide results within 15 minutes. More than 60,000 antigen tests were administered a year ago; this year’s count to date is under 21,000.

Flu activity nationwide was down this year, due in part to a flu vaccine that was much more effective than the one formulated last winter, he said.

The vaccine is developed months earlier and sometimes can be less effective if the virus changes makeup before the flu season begins.

“This was a very good vaccine for the A virus. The B virus was not as good a match, but usually we have a lot fewer B cases than A cases,” said Kightlinger. “But we can’t count it all to the vaccine. Maybe we have a less virulent virus circulating this year.”

Influenza can produce a sudden fever, headache, dry cough, sore throat, runny or stuffy nose, and muscle aches.

The elderly and the young are especially vulnerable. Children haven’t built up a natural immunity. In the elderly, the immune system isn’t as strong.

The three people who died in South Dakota were elderly. Nationally, 36 children died, Kightlinger said.

More than 91,000 doses of flu vaccine were given in South Dakota this season to children ages 6 months to 18 years in a Health Department vaccination initiative. Last year’s program provided 72,000 flu shots.

The Health Department focuses on young people because they account for a large percentage of the flu cases and often are more likely to spread the disease.

Forty-six percent of those hospitalized this year were age 9 or younger. Thirteen percent of the hospitalizations involved people age 70 or older.

Kightlinger said this year’s flu season peak in the second week of March is later than usual.

“Nobody has a good explanation why it starts and ends ... it’s one of the great unknown questions, but we know that every year influenza comes and then runs its course and goes away. And six months later it will be back.”

Tags: news, flu