The rate of influenza hospitalizations this flu season is the highest in nearly a decade, according to CDC data released Friday.
The latest CDC data cover the week ending Jan. 27. According to the Washington Post's "To Your Health," experts have compared this season to the especially severe 2014-2015 season, when the same strain, H3N2, predominated.
The latest CDC data show 51.4 hospitalizations per 100,000 individuals in the general population this flu season—the highest recorded rate since the agency began using its current methodology in 2010, and nearly as high as the rate during the swine-flu pandemic in 2009, "To Your Health" reports. By comparison, during the same period in the 2014-2015 season, there were 43.5 hospitalizations per 100,000 individuals.
In California, hospitalization rates are four times those of the 2014-2015 season, while rates in Minnesota and Oregon are double those of 2014-2015, according to the Washington Post's "To Your Health." According to CDC, the hospitalization rate is highest among adults age 65 and older, with the next-highest rates seen among adults ages 50 to 64 and children younger than five.
Outpatient visits for flu symptoms also increased, accounting for 7.1% of outpatient visits, CDC reported. The agency said only two previous flu seasons over the past 16 years have led to higher outpatient visit rates.
Overall, pneumonia and flu were related to 9.7% of all deaths during the week ending Jan. 27, which is above the "epidemic" threshold for the third consecutive week. Most flu-related deaths this season have been among adults over age 65 and children, which is typical, according to NPR's "Shots."
Flu has caused at least 53 deaths among pediatric patients so far this season, according to CDC, with 16 occurring in the latest reporting week. Of the children who have died from the flu, about 50% appeared to be otherwise healthy and did not have special vulnerability to the flu—although about 80% had not received the flu shot, according to CDC Acting Director Anne Schuchat.
Flu remains widespread in 48 states, according to the latest CDC data. Flu was widespread in 49 states in the previous reporting week, but Oregon no longer is reporting widespread flu, according to CDC.
CDC said they are hopeful that this marks the beginning of a trend of reduced flu activity in the western part of the country—but they cautioned that flu season is by no means over. Schuchat said the country is "by no means out of the woods," and that flu activity is increasing in the East and is hardly changed in the South.
The week ending Jan. 27 was the 10th week of flu season. An average flu season last 16 weeks, but the season can run as long as 20 weeks.
Still get vaccinated, watch for symptoms, CDC urges
Officials again urged individuals who haven't received a flu shot to get one, although they acknowledged that they cannot yet determine the effectiveness of this year's vaccine. According to "To Your Health," the annual flu shot tends to be less effective when the H3N2 is the predominant strain, as it is this year.
Officials have said they expect this year's shot will have a 32% effectiveness against circulating H3N2 viruses, though researchers in Canada last week said they project 17% effectiveness against H3N2, according to "To Your Health."
Schuchat also urged parents to watch for symptoms of severe illness, such as very high persistent fever, difficulty breathing, rapid heartbeat, and significant fatigue or confusion. Further, if the condition of a person—adult or child—appears to worsen, it could be a sign of secondary infection (Bealsey, Reuters, 2/2; Sun, "To Your Health," Washington Post, 2/2; Harris, "Shots," NPR, 2/2; Walker, MedPage Today, 2/2; "FluView," CDC, 2/2).
Traveling this winter? How to avoid the flu when you fly.
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