Adults Get The Flu Twice a Decade: Study

Adults get the flu at least once every five years, according to a new study released Wednesday.

"For adults, we found that influenza infection is actually much less common than some people think. In childhood and adolescence, it's much more common, possibly because we mix more with other people," said Steven Riley of Imperial College London, who worked on the research, according to a Reutersreport.

"The exact frequency of infection will vary depending on background levels of flu and vaccination."

Meanwhile, children catch the flu once every two years but flu infections become rarer as people move from childhood to early adulthood.  By the age after 30, flu occurs only at a steady rate of about once every five years.

For the study, an international team of researchers analyzed blood samples from 151 volunteers from China between the age of seven and 81.

Researchers looked at the nine main flu strains that circulated around the world from 1968 to 2009. All the strains are types of influenza A (H3N2) virus.

There has been a lot of debate about how often people get flu as opposed to flu-like viruses. Professor Ron Eccles, director of the Common Cold Centre in Cardiff tells us: "There is much confusion betweencolds and flu and influenza.

"Colds are a mild illness caused by common cold viruses and influenza viruses; flu is a more severe illness with cough and fever caused by colds viruses and influenza viruses, but influenza is an infection caused by only influenza viruses and it can cause a cold or flu or even no symptoms at all."