Angela Minicuci, spokeswoman for the Michigan Department of Community Health said it confirmed 169 cases of the flu as of Thursday, up from 63 cases the previous week, a higher-than-normal rate for this time of year, The Detroit News reported.
The actual rate of influenza is much higher because the confirmed cases are those being treated by a physician and tested for influenza.
More than 50 percent of the reported cases of influenza were recorded in the southeastern part of the state, which has the largest population, Minicuci said.
"We really don't know why, but we do know that the strains of flu we're seeing are all pretty well-protected by the flu vaccine," Minicuci told the News. "Anyone who receives the vaccine will have a pretty good shot at being protected during the flu season."
Flu season can last as long as May, so it's not too late to get an influenza vaccine.
The Centers for Disease Control and Prevention in Atlanta recommends all people older than six months get a annual seasonal flu shot.