Influenza has reached every geographic region of the state of Iowa according to a statement released Monday by the Iowa Department of Public Health (IDPH). Officials have now categorized the outbreak as “widespread” — the highest level of activity possible as specified by the Center for Disease Control (CDC).
In the last week, Iowa has seen 130 influenza-related hospitalizations, according to the Iowa Influenza Surveillance Network, mostly among those age 64 or older.
Four different influenza strains have been identified this year, with A(H3N2) — an especially nasty strain — being the most common. The flu season tends to be more severe in years when A(H3N2) strains dominate, the IDPH states.
What’s more, the current A(H3N2) strain is not covered in this year’s vaccine.
“The B strains and the H1N1 are well-matched to what’s circulating in the U.S. right now,” said Deputy State Epidemiologist Ann Garvey. “But the A(H3N2) strain has drifted from what’s currently in the vaccine.”
Garvey says this “drifting” — slight changes to the virus — happens every year.
“Sometimes, with these variants, there’s a little bit of spread and they fizzle out, and there’s not a lot of activity,” Garvey said. “And sometimes, they seem to take off a little bit more.”
This year, the drifted A(H3N2) strain did anything but fizzle out. Officials first started noticing the strain this past March, which turned out to be too late.
“In order to get a vaccine produced for the fall, we have to make the decision about what viruses are going to be included in February,” Garvey said. “So this drifted strain first started to be seen in the March time frame, and over the summer months and this fall, it became more and more common in circulation.”
In other words, the strain of A(H3N2) in the vaccine is different from the more common A(H3N2) strain currently in circulation.
“We know this drifting occurs all the time,” Garvey said. “It was just a situation where this virus started circulating after we had to make that decision.”
On average, about 300,000 Iowans get the flu each year according to the CDC, which causes about 1,000 deaths annually — typically in the very young and very old.
The IDPH says the flu vaccine is still the “best defense” for safeguarding against influenza, despite how common the drifted strain has become.
“There’s a lot of protection to be had by getting the vaccine, even this late in the game,” Garvey said. “Because, again, while we’re seeing the [drifted strain] most commonly .. We’re also seeing circulation of those two B strains and H1N1,” which are covered in this year’s vaccination. “While it’s not as good of protection as we’d like, we still think that it gives partial protection,” she said.
Garvey says that although influenza affects the young and old most severely, healthy adults should still seek medical guidance when faced with severe symtpoms.
“Anytime that you have more severe symptoms, certainly if you have difficulty breathing, a rapid onset of a high fever — that type of thing — it would be appropriate to call your healthcare provider and seek guidance,” Garvey said.
Garvey recommends anti-viral medication for high-risk individuals — the elderly, the young and those who have unrelated illness.
“That’s a treatment that can help decrease the severity of their illness, possibly shorten their illness and keep them from developing severe symptoms and possibly dying,” Garvey said, adding that these anti-virals, such as Tamiflu, work best when given within the first 48 hours of illness.
