DETROIT – Metro Detroit doctors said we are still in the grips of the flu, but that’s not the only illness to be concerned about. The flu season is in full swing and doctors are consistently seeing cases of influenza A and influenza B. There are also a lot of other illnesses circulating as well. If you are sick with a respiratory virus, ordinary masks can help keep you from spreading an infection to people. If you are not sick you should not substitute a mask for other hygiene like handwashing.