It’s March, and normally the winter flu season in the U.S. would be winding down. This year is different: Flu cases are still on the rise this year after a very late start.
Every year, the U.S. Centers for Disease Control and Prevention announces the start of the flu season based on testing done around the country. When people go to their health provider complaining of a flu-like illness, they often get tested for the flu. When more than 10 percent of sick people test positive, that’s the official “start” of the U.S. flu season.
This year, the flu season didn’t officially start until February, which CDC calls “the latest start to a flu season in the past 29 years.” Since then, cases have been slowly rising. Last week, more than 23 percent of sick people around the country tested positive for the flu.
Why is the flu season off to such a slow start? Influenza is unpredictable, but there could be a few reasons. Abnormally warm weather around the country could have made it harder for the flu virus to survive. Also, the number of people getting seasonal flu shots increased in 2011, so that could help explain why less people have come down with the flu this year.
Public health officials aren’t sure if the 2011-2012 flu season will get worse in the coming weeks or if the season will end with a surprisingly low number of infections. The good news is that the viruses going around this year — H1N1, H3N2 and influenza B — are all covered in the seasonal flu shot. So no matter what happens, if you haven’t gotten your flu shot yet, there’s still time!
You can visit the CDC Flu Activity page to learn more about the current flu season. You can also help map the flu season this year even if you aren’t sick — check out our Flu Near You tool to report your symptoms and find out if there is flu in your neighborhood.
|Flu Near You screenshot courtesy Flu Near You|