Flu activity in the United States has really taken off, the Centers for Disease Control and Prevention reported on Friday.
A number of modeling experts the agency works with are predicting that this year’s flu season will peak around the end of this month, Dr. Daniel Jernigan, head of the agency’s influenza division, told STAT.
That means lots of people will be sick over the holidays; lots already are. And the multi-generational family gatherings that are part and parcel of the holidays will fuel the spread of the nasty virus.
“Thinking about folks that are traveling right now, it would be fruitful for them to know that flu could be traveling with them,” Jernigan said.
The CDC reports weekly — on Fridays — on the status of flu activity during the season. There is a one-week lag in the data, so Friday’s snapshot reflected how things stood through the week that ended Dec. 16.
The graph of outpatient illness surveillance — which records the portion of people who sought health care because of flu-like symptoms — shot up from the previous week and appears to be on the same trajectory as the 2014-15 flu season, which also started early and was a severe year.
The most recent data show flu is raging in 23 states, compared to 12 states the previous week.
“We’re continuing to see an increase — and a pretty sizeable one,’’ said Dr. Alicia Budd, an epidemiologist in the Jernigan’s division.
But that curve only tells you there’s a lot of flu around, Jernigan warned. It is not an indicator of the severity of the flu season.
This year could well be a severe year. The viruses causing most of the illness right now are from an influenza A family called H3N2. Those viruses are especially hard on older people and H3 seasons generally are more severe that seasons when H1N1 or influenza B viruses are dominant.
Unfortunately the H3N2 component of the flu shot is an under-performer, often offering protection that is in the 30 percent range. (The other components more commonly offer between 50 percent and 70 percent protection.) So even people who have been vaccinated may find themselves coming down with flu, Jernigan said.
“While it may be an early season and it will be an H3 one for sure – so far – whether it’s worse than we would expect, I don’t know that we have any information to support that at this point,” Jernigan noted.
“But clearly, it’s enough for us to say [to] everybody who’s getting ready to go and visit their grandmother and their families in the next few weeks, that from these data, it indicates that there may be a fair amount of flu circulating around that time.”
He suggested people who are sick should do their relatives and friends a favor and stay home from holiday gatherings. “If you know you have flu, it is really important to not share that, especially with those who are at highest risk of severe disease,” he said.
The CDC is urging health care professionals to be aware of the fact that even vaccinated patients may get the flu this year, Jernigan said. Patients who have other health conditions that predispose them to getting very sick when they contract influenza should be prescribed anti-viral drugs, he said.