Hospitals are only required to report pediatric flu deaths, said David Jackson, an epidemiologist with the health department. "Even if [an adult] dies from the flu, it's rare that it's reported that way."
The cause of death can be difficult to ascertain because it might be reported as pneumonia or a cardiovascular complication, even though it started with the flu, Jackson explained.
But the U.S. Centers for Disease Control and Prevention estimate that 36,000 people die annually from the flu. So far this season there have been four pediatric deaths nationwide, the CDC says.
And while there have been no reported deaths in Utah, the state usually sees between one and three pediatric deaths a year.
The risk underscores the importance of getting vaccinated, said Jackson, noting that this year's vaccine covers four strains, including the predominant one circulating now H1N1 or swine flu.
Swine flu is responsible for more than half of the 168 flu hospitalizations reported in Utah since the season's start in October, he said.
Swine flu shook the public health world in 2009 in part because, when it surfaced, it behaved differently than other strains. Instead of seeing hospitalizations mostly among the young and old, healthy adults ages between 25 and 49 proved especially vulnerable.
"It is our seasonal flu now," said Jackson.
It's not too late to get immunized, and there's ample supply of the vaccine, but the sooner the better, say health officials, stressing it takes two weeks to develop full immunity.