Flu incidence crests at 6.6%, highest in this decade
The good news to come out of Friday morning's CDC Flu View news conference is that we are about halfway through the season. The bad news is we still have half a season to go, and this season has been the worst in flu incidence since the 2009 H1N1 pandemic.
That year, flu incidence reached a peak of 7.7%. For the week ended Jan. 20, flu incidence crested at 6.6% nationwide, though there were signs that flu incidence rates were declining in some parts of the country.
"It has been a tough flu season so far this year," Dan Jernigan, director of the influenza division in CDC’s National Center for Immunization and Respiratory Diseases, said. "This rapid increase in cases that we've been seeing is after the winter holidays and it is among all ages but it is higher among children. So it looks like a big part of the later January activity is flu transmission from kids returning to school."
And it's not abating. "While flu activity is beginning to go down in some parts of the country, it remains high for most of the U.S. with some areas still rising. Most people with influenza are being infected with the H3N2 influenza virus. In seasons where H3N2 is the main cause of influenza, we see more cases, more visits to the doctor, more hospitalizations and more deaths, especially among older people," Jernigan said. "We've experienced two notable characteristics of flu this season. The first is that flu activity became widespread in almost all states and jurisdictions at the same time. The second notable characteristic is that flu activity has now stayed at the same level at the national level for three weeks in a row with 49 states reporting widespread activity each week for three weeks."
The 2017/2018 influenza season is nine weeks old. The average season over the past five years is 16 weeks, with the longest season in the past five years extending 20 weeks. "In past seasons that are like this one, we have estimated that by the end of the season, 34 million Americans had gotten the flu," Jernigan said.
"The flu season is continuing to be challenging and flu has been intense across the United States," Brenda Fitzgerald, director CDC , said. "Remember, it's not too late to get a flu shot for yourself and for your child."
That year, flu incidence reached a peak of 7.7%. For the week ended Jan. 20, flu incidence crested at 6.6% nationwide, though there were signs that flu incidence rates were declining in some parts of the country.
"It has been a tough flu season so far this year," Dan Jernigan, director of the influenza division in CDC’s National Center for Immunization and Respiratory Diseases, said. "This rapid increase in cases that we've been seeing is after the winter holidays and it is among all ages but it is higher among children. So it looks like a big part of the later January activity is flu transmission from kids returning to school."
And it's not abating. "While flu activity is beginning to go down in some parts of the country, it remains high for most of the U.S. with some areas still rising. Most people with influenza are being infected with the H3N2 influenza virus. In seasons where H3N2 is the main cause of influenza, we see more cases, more visits to the doctor, more hospitalizations and more deaths, especially among older people," Jernigan said. "We've experienced two notable characteristics of flu this season. The first is that flu activity became widespread in almost all states and jurisdictions at the same time. The second notable characteristic is that flu activity has now stayed at the same level at the national level for three weeks in a row with 49 states reporting widespread activity each week for three weeks."
The 2017/2018 influenza season is nine weeks old. The average season over the past five years is 16 weeks, with the longest season in the past five years extending 20 weeks. "In past seasons that are like this one, we have estimated that by the end of the season, 34 million Americans had gotten the flu," Jernigan said.
"The flu season is continuing to be challenging and flu has been intense across the United States," Brenda Fitzgerald, director CDC , said. "Remember, it's not too late to get a flu shot for yourself and for your child."