(Bloomberg) — Family gatherings helped spread influenza during the 2013 holiday season, as the pace of flu reports jumped at year end, according to the U.S. Centers for Disease Control and Prevention (CDC).
About 4.3 percent of doctor visits during the week ended Dec. 28 were for complaints of flu-like symptoms such as fever, coughs and sore throats, more than double the national baseline of 2 percent, and a 50 percent increase from the week earlier, the CDC said.
While the outbreak is mimicking last year’s fast and intense season, though delayed by a few weeks, the illness is hitting hardest in a different group of patients.
“Normally we think of elderly people, 65 years of age and older” as those most affected by influenza, said Michael Jhung, a medical epidemiologist for the CDC in Atlanta. “This year, young- and middle-aged adults are being hit hard by flu. People aren’t expecting to hear about severely ill young- and middle-aged adults.”
Twenty states, composed of most of the southern U.S. from North Carolina to Nevada, are reporting widespread influenza activity, with eight experiencing moderate levels.
Sixteen states, including all of New England and California, say they have minimal influenza activity. Deaths from pneumonia and influenza remained below baseline levels nationwide, with six children dying from flu-related complications so far this season, the CDC reported.
The most widely circulating virus seen so far this season is H1N1, known as swine flu when it first came to prominence in 2009 and now considered a routine part of influenza activity, Jhung said.
“During the 2009 pandemic, school-aged children were heavily hit, and we do expect to see illness in all age groups,” he said. “We are seeing a lot of illnesses in those age groups now, and we are unfortunately seeing a lot of severe illnesses.”
The season hasn’t yet peaked, with weeks or months left until influenza is no longer swirling across the country, Jhung said. While there was a substantial increase in the number of cases reported at the end of the year, the surge is typical and there’s no way to know how severe the season will be, he said.
Flu activity picked up quickly in December on Google Inc.’s Flu Trends function, an aggregation of search terms that indicate people are looking for information about the virus. Levels were low on Dec. 8, moderate on Dec. 15 and high for the past three weeks. The chart is often a leading indicator for higherflu rates later reported by the CDC.
For those who are severely ill or have other medical problems, Roche Holding AG’s Tamiflu or GlaxoSmithKline Plc’s Relenza anti-viral treatments may offer some relief, he said.
It’s too early to say definitively that the vaccines crafted for this year’s season are holding the virus at bay, Jhung said. Still, of the nearly 400 specimens of H1N1 virus that have been examined in detail at CDC, all had a component similar to what was included in the vaccine, he said. Every immunization offered this year includes protection again H1N1.
“Getting a vaccine should provide protection against H1N1, which is the most widely circulating virusright now,” he said. “It’s not too late to get it. The peak will probably come in January or February. There is still time to protect yourself for these last few months.”