Dr. Joseph Bresee, chief of the epidemiology prevention branch at the influenza division at the Centers for Disease Control and Prevention, said for the third consecutive week this season the percent of respiratory specimen testing positive for flu surpassed 10 percent, which is generally a marker to indicate the flu season has begun.
Based on CDC flu surveillance data, the only other time this has occurred was the 1987-1988 season, Bresee said.
Despite flu activity being low from early October through January, influenza viruses have been reported from all 50 states and is widespread in California and Colorado.
Influenza A, H3N2 viruses, 2009 Influenza A H1N1 viruses and Influenza B viruses have all been identified this season in the United States.
"Regional influenza activity was reported in 13 states and increased from 12 last week. And 20 states reported local influenza activity and increased from 17 last week," Bresee told reporters on a conference call.
"We can't predict the timing of peak activity in the United States nor when the season will end, nor can we predict how severe the season will ultimately be. So if you haven't gotten the flu vaccine yet or your loved ones haven't gotten theirs yet, get your vaccine now."