The number of flu-related deaths in South Dakota this past season has been the highest since 2004.
There were 38 influenza-related deaths in the 2012-13 flu season as of April 27, the latest report, said state Epidemiologist Lon Kightlinger. In 2004, there were 42 deaths reported in South Dakota.
There's a possibility that the death numbers will rise if more flu-related deaths are reported, Kightlinger said.
A majority of the deaths were in the elderly population, Kightlinger said. Deaths by age group:
- 0-4 years old: one.
- 5-24: two.
- 25-49: zero.
- 50-64: one.
- 64 or older: 34.
"Every year, every month the virus is always evolving and changing," Kightlinger said. "This year, it just got some tough genes in it and it just became more virulent."
Brown County saw three flu-related deaths so far this season and Edmunds County saw one, according to data from the South Dakota Department of Health.
The flu vaccine was 62 percent effective, meaning that of 100 people, 62 would stay well and 38 would get sick, Kightlinger said.
"It's not 90 percent, but it's the best weapon we have. It's better than locking yourself in your bedroom between October and April," Kightlinger said.
As far as the weather and temperature causing the spread of the flu, there is not a strong correlation, he said.
"All you have to do is look at the state of Alabama, which has very little snow and it doesn't get cold at all. They had as much influenza as we did," he said.
Because the virus was so potent this season — in South Dakota and across the nation — flu manufacturers are strengthening the flu vaccine for the upcoming season, Kightlinger said.
Normally, the vaccine is effective against three strains of the virus that health officials identify as the most predominant for the upcoming season, Kightlinger said. But this past season, there was a strain of the virus that the previous vaccine didn't fight against. Because of that, manufacturers are producing a vaccine that will fight four strains of the virus, he said.
"We could prevent more cases if we had (this additional) virus component in the vaccine," Kightlinger said.
People will be able to ask for the three- or four-strain vaccine come fall depending on the availability. Kightlinger said the prices for vaccines that fight against the four strains will probably be more expensive.
The state Department of Health, which offers free vaccines for children, is ordering both versions, Kightlinger said.
"Hopefully we'll have a very good match next year," he said.