Arizona’s busy flu season, fueled by the H1N1 strain, has been unusually harsh on young adults, Tucson-area medical experts say.
“Usually flu affects the very, very young and very, very elderly. This year we are seeing young adults getting very sick and ending up in the ICU, so it’s a little bit of a different population with this flu,” said Dr. Rick Anderson, chief medical officer for Tucson Medical Center, which is Tucson’s largest hospital.
Unlike the last flu season, the H1N1 strain of influenza is circulating this season, and H1N1 tends to disproportionately affect otherwise healthy young adults, said Dr. Sean P. Elliott, medical director of infection prevention at Banner-University Medical Center Tucson.
“The principal strain circulating is the Influenza A, H1N1, which is the 2009 pandemic strain that was so deadly,” Elliott said. “That strain is causing about 70 percent of flu in Arizona right now and it’s causing severe, bad flu. So to have any protection from the vaccine is a very good thing.”
suddenly sick
State data show 56 percent of this season’s confirmed flu cases have been in Arizonans ages five through 49 . Just 13 percent have been among people 65 or older.
Young adults may not always be getting their flu shot, Elliott said. But even if they do get vaccinated, some will still get sick.
“When you have certain strains, especially in a pandemic setting like 2009, they disproportionately affect a group of people who shouldn’t normally be that sick,” Elliott said. “This goes back historically to experiences from the 1918 Spanish flu. It was those healthy young soldiers who got sick. Part of it may be clustering, part of it may be very healthy young immune systems that react almost too strongly to a viral challenge.
“There’s a whole bunch of hypothetical explanations. But I’ve not seen convincing data to support one versus the other.”
At least one local patient with severe flu this season has ended up needing a last-ditch therapy known as ECMO — extracorporeal membrane oxygenation, which is an external lung machine and highly specialized form of life support, Elliott said.
Puerto Rico and six states — Arizona, California, New Mexico, North Carolina, Texas, and Utah — have high levels of flu activity now, while the rest of the states have low or moderate flu activity, the U.S. Centers for Disease Control and Prevention reports.
We’re No. 1
The most recent federal data says Arizona has the highest level of flu activity in the country, said Dr. Cara Christ, director of the Arizona Department of Health Services.
“Right now we are number one,” Christ said. “We did have a pretty significant increase over two weeks of flu cases that were reported.”
One possible reason for Arizona’s high activity level is that the state has an extremely effective influenza monitoring system, “so we capture a lot of cases,” Christ said.
“The other thing is if you look at the progression of how flu travels around the world, it kind of comes through South America up through Central America into North America. So the Southwest is kind of the entry point.”
Arizona’s high level of flu activity is fueling a spike in local emergency department visits that may result in longer waits, hospital officials say.
Pima County has so far this season accounted for 23 percent of all the flu cases statewide, with a total of 1,697 confirmed cases, data from the Arizona Department of Health Services shows.
Emergency rooms hit
Patient visits to Tucson Medical Center’s emergency department are up 10 percent over this time last year, Anderson said. Volume has reached nearly 400 emergency department patients in a 24-hour period, he said.
Symptoms of the flu include a fever of more than 100 degrees, a headache, body aches, and a lower respiratory infection — not typically a runny nose or vomiting and diarrhea, but rather a cough.
“There are other viruses out there. But at least over the last several weeks, when we hit widespread flu for the state, every emergency department in the entire region, in the entire state, has seen a significant increase in patient volume,” Elliott said.
There are always people who overuse emergency departments as a source of primary care, and local hospital officials are urging Pima County residents not to go directly to the ER but to call their primary-care doctor if they think they have the flu.
“The (influenza) challenges that are sending patients appropriately to the ER are severe dehydration and breathing problems, respiratory distress — the need for oxygen,” Elliott said.
shot 59 % effective
Medical experts say it’s not too late to get a flu shot. The CDC recently reported a preliminary overall influenza-vaccine effectiveness of 59 percent this season. Last year’s effectiveness was 23 percent.
“This means that getting a flu vaccine this season reduced the risk of having to go to the doctor because of flu by nearly 60 percent,” Dr. Joseph Bresee, chief of CDC’s Epidemiology and Prevention Branch, said in a news release.
“It’s good news and underscores the importance and the benefit of both annual and ongoing vaccination efforts this season.”
It’s not too late
The CDC reports that the vaccine formula this season has a 51 percent effectiveness against the H1N1 viruses responsible for most flu illness this season.
“You never can tell in the thick of the season how good a match it is going to be other than some predictive modeling,” Elliott said. “The strains recorded through the Arizona Department of Health Services are indeed those being covered by the vaccine.
“No vaccine in this situation is going to prevent the flu 100 percent of the time,” Elliott said. “What we are seeing, and I think what the entire area is seeing, are patients who did get the vaccine and still got sick with the flu, but it’s a much more mild version that it would have been otherwise. It might not feel that way to them.”
The most important thing Arizonans can do is get vaccinated. It is not too late, Christ said.
“Our flu season, while it peaks in January, February and into the beginning of March, we will see cases through May. And it does afford you some protection into the next season.”
Officials with the Pima County Health Department say they want to remind the public to be vigilant about hand-washing and also to stay home if you are sick.
