Officials say there's been a five-fold increase of cases of a new strain of swine flu that spreads from pigs to people.
The case count jumped from 29 a week ago to 145 this week, thanks to a wave of new cases confirmed in Indiana and Ohio.
The good news is the flu does not seem to be unusually dangerous, like the strain in 2009 that killed at least 12,000. Two of the new patients were hospitalized, but most illnesses have been mild and no one has died. Most or all of the cases appear to have spread from pigs to humans, meaning it's not very contagious.
The Centers for Disease Control and Prevention released the new numbers on Thursday. The patients were infected a week or two ago.