MURRAY — A change in vaccination priorities should be considered for future novel H1N1 influenza outbreaks, say researchers at Intermountain Medical Center who have completed a new medical study.
When H1N1 surfaced last year, children, pregnant women and people with lung problems were included in the first priority vaccination group. However, a new study published in the April issue of Chest, the scientific medical journal of the American College of Chest Physicians, found a pattern unique to any previous flu outbreaks.
The sickest patients being admitted to intensive care units were more likely to be young adults, obese, Hispanic or Pacific Islander and less likely to be insured.
"This information exemplifies how H1N1 affects a different population than seasonal influenza," said Dr. Russ Miller, medical director of the respiratory Intensive Care Unit at Intermountain Medical Center and the study's lead investigator.
Speaking at a press conference Monday morning at the medical center, Miller stressed that the matter of whether future vaccination priorities change is up to the Centers for Disease Control and Prevention and/or the Utah Department of Health.
The omission of these new groups potentially cost lives and cost hospitals and taxpayers millions of dollars.
"This was somewhat unique in medical illness," he said. "It is an interesting finding."
He cautioned that further study needs to be conducted and that it is not scientifically clear why these new groups were more vulnerable to the swine flu.
"We don't know how all of these things are related. … One has to be careful jumping to conclusions," he said. "It suggests avenues for further research."
For the study, researchers examined the records of 47 of the first group of confirmed H1N1 patients admitted to adult intensive care units at Intermountain Medical Center, LDS Hospital and the University of Utah Health Sciences Center between May 19 and June 30, 2009 — the first period of H1N1 outbreaks in Utah. This information was then compared to influenza statistics for the general population of Salt Lake County.
Seasonal influenza usually strikes children and the elderly the hardest. In contrast, H1N1 struck young adults between the ages of 15-34 the most — as well as a new group, the obese.
Miller said in general terms, the larger the patient, the most common hospital admission is that studies in animals have found a link between illness and obesity.
But whether the CDC will add obesity as a new H1N1 risk factor is still unknown.
Miller also said while two-thirds of the H1N1 patients admitted to the hospital had some of the known high-risk factors, most of the remaining one-third were obese or smokers.
While all patients were critically ill when admitted to the ICUs with H1N1, Hispanics and Pacific Islanders were among the sickest and comprised 23 percent and 26 percent respectively.
Despite the omission of the possible new risk groups, there was still an 83 percent survival rate of those in Salt Lake County admitted to the hospital with H1N1.
The new study also found that 45 percent of those admitted to the ICUs had no health insurance and 21 percent only had public insurance (Medicaid, Medicare or CHIP).
It is still unclear if a third-wave outbreak of H1N1 will appear, but Miller said that is looking less likely as more time passes.
The complete new study, as published in the April issue of Chest, is available online at: chestjournal.chestpubs.org/content/137/4/752.full.html.
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