The burden of influenza has never been this high since the 2009 H1N1 swine flu pandemic. This is the metric the CDC uses to estimate season severity based on laboratory-confirmed cases, doctor visits, hospitalizations, and deaths.
Epidemiologist Lynette Brammer, who leads the CDC’s National Flu Surveillance Team, said, “Although it’s rare, we’re coming out of an unusual covid pandemic that has really affected influenza and other respiratory viruses.
Activity is high in the southern and southeastern United States and is beginning to migrate to the Atlantic coast.
The CDC tracks flu in a number of ways, including estimating the rate of doctor visits for flu-like illnesses. However, given similar symptoms, people seeking treatment for covid-19 and RSV, another respiratory virus with similar symptoms, Laboratory data leaves no doubt.
“Data is ominous,” said William Schaffner. He is the medical director of the non-profit National Infectious Diseases Foundation and Professor of Infectious Diseases at the Vanderbilt University School of Medicine. “Not only is the flu in its early stages, it looks very severe. is.”
Adding to his concerns, he said flu vaccinations have lagged behind normal at this point in the season. At this point last year it was 139 million, and the year before last it was 154 million, according to the CDC.
“It worries me doubly” Schaffner Said. The heavy burden of the flu “certainly looks like the beginning of the worst flu season in 13 years.”
The number of flu cases this season is one-eighth of last season’s estimated total of 8 to 13 million cases.
The latest flu data comes as the country’s strained public health system grapples with multiple viral threats. coronavirus Cases are expected to rise as the country heads towards cooler weather and more people congregate indoors.new covid-19 variants improved ability to evade immune defenses, 27% of casesup from 17% a week ago. lots of children’s hospitals With record numbers of children infected with RSV.
According to the CDC, the flu vaccine’s effectiveness in preventing doctor visits, hospitalizations, or deaths varies from year to year, hovering between 40% and 60% over the past few years. However, Brammer et al. say this season’s vaccine is well-matched against the circulating strains. According to Schaffner, this provides “a little bit of sunshine” in what can be a harsh winter.
Nationwide, the dominant virus — a particularly nasty strain, H3N2 — causes the worst outbreaks of the two. Influenza A virus and two types of influenza B virus that circulate among humans.season H3N2 dominance It typically causes the most complications, experts say, especially for the very young, the elderly, and people with certain chronic health conditions.
What many people don’t realize is that even after someone recovers from the flu, the inflammatory response generated by the virus continues to wreak havoc in middle-aged and older people for another four to six weeks, reducing heart attack rates. It means that it is increasing. And a stroke, Schaffner said.
Influenza has not been a serious problem in the past two years, experts and health officials say. maskingsocial distancing and other measures people have taken to protect themselves from covid-19.
Health officials say flu season has officially begun after several weeks of uninterrupted flu activity from several surveillance systems, including a significant percentage of clinic visits for flu-like illness. These doctor visits were up for the third straight week as of Oct. 22, more than a month earlier than the previous season, said CDC’s Brammer. .
Influenza is notoriously difficult to predict. It is difficult to know how long the season will last, how severe it will be, and whether different parts of the country will experience different levels of respiratory illness at different times. peaked in January, “then dropped like a stone, then smoldered past March into April, May and June, just below the epidemic threshold,” Schaffner said. states that its “long smoldering tail was very unusual.”
“Early starts aren’t always serious,” says Brammer.
In the southern hemisphere, flu seasons are also very different, said Brammer. In Argentina, influenza activity peaked during what should have been the country’s summer.
“Things haven’t returned to their normal patterns,” Brammer said.
Chile weathered a severe flu season that began months earlier than the normal season by rapidly vaccinating 88% of its high-risk population before flu activity peaked. CDC report this week. Influenza vaccines used in Chile, containing a match for the H3N2 virus that predominates in him, were about 50% effective in preventing hospitalization. Shots used in the northern hemisphere contain the same viral composition as vaccines in the southern hemisphere, so experts say the formulation could be equally effective in preventing severe flu illness. I hope that
The latest CDC data show that overall respiratory disease activity is “very high” in South Carolina and DC, with Alabama, Georgia, Louisiana, Maryland, Mississippi, New Jersey, New York, North Carolina, Tennessee, Texas and Virginia.
Texas was one of the earliest states to see flu activity in late September. The Houston Methodist Hospital system had 975 laboratory-confirmed flu cases as of Oct. 20, up from 561 the previous week, officials said.
With so many people dropping protective measures against COVID-19 and being hesitant to get vaccinated, officials were preparing for a more active flu season this fall and winter.
“We are a hub and a lot of people travel here, so this was what we expected,” said César Arias, the hospital system’s head of infectious diseases. rice field. But he said, “I didn’t expect to see so much. [flu] That’s early.”
According to Arias, conversations about flu vaccinations hesitation About the coronavirus vaccine. The conversation in Texas was, “As you can imagine, [are] Stronger, or at least more vocal,” he said. “We are struggling with trying to get the message out to get vaccinated.”
People need to be protected with a new flu vaccine each year, and it can take up to two weeks for protection to kick in and for the vaccine to work. The CDC recommends that everyone over the age of 6 months should get her flu vaccine, ideally by the end of October.
