Levels of influenza nationwide are now at the highest they have been since the peak of the 2009 swine flu pandemic, according to figures published Friday by the Centers for Disease Control and Prevention, amid this winter’s second wave of the virus.
Close to 8% of visits for respiratory illness to outpatient providers, including urgent cares and doctors offices, reported to the CDC this week were people sick with influenza. That is the worst on record in the CDC’s influenza surveillance network since late 2009, during the swine flu pandemic.
While most flu seasons usually see a resurgence of infections after the winter holidays, this winter’s flu wave has now reached unusually high levels compared to recent years.
That has driven overall levels of respiratory illness to “very high” levels for the first time this season, despite a smaller and now-decreasing wave of COVID-19 in recent months.
Other influenza metrics are also far above recent peaks nationwide, including in emergency rooms and from testing laboratories. Data collected by the CDC from labs found 31.6% of tests last week were positive for influenza, close to double the 18.2% at last season’s peak.
The CDC says that most states are at “high” or “very high” levels of influenza activity, though some states may have now reached their peak.
Centers for Disease Control and Prevention
Influenza infections are “likely growing” in 15 states, the agency’s disease forecasters predict, and are either now flat or starting to decline in most other states.
One of the states where influenza is “likely growing” is Kentucky, where pediatric infectious specialist Dr. Kris Bryant says she’s seeing “extraordinarily high numbers” of positive cases in children. At Norton Children’s Hospital, there were 3,000 positive cases just last week, she said, calling the uptick “worrisome.”
“We tend to focus on flu as a respiratory viral illness, but some parents don’t realize that it can cause seizures, even rarely an inflammation of the brain, and pediatricians are reporting cases of that across the U.S.,” Bryant said.
Flu vaccination rates in children is at its lowest level in six years, according to the CDC. This year, fewer than half of Americans have been vaccinated. Bryant suspects “vaccine hesitancy” could be playing a role in the trend.
Unlike the 2009 pandemic, lab tests around the country suggest cases are still from the usual seasonal variants of the virus, and not a new strain that has spilled over from animals.
While farms have been grappling with a record surge of H5N1 bird flu in poultry driving up egg prices, and a new potentially lethal strain in dairy cows, only a handful of human cases have been confirmed from bird flu in the U.S. Investigations have linked cases to direct contact with sick animals, not human-to-human transmission.
contributed to this report.
