Steven Salzberg, at Forbes Magazine, has reported that the USA is experiencing the worst whooping cough epidemic in 70 years. In addition, the CDC has stated that as of August 4 2012 (pdf), there are 21,000 cases and 10 deaths in the United States from whooping cough(Bordetella pertussis) year-to-date. Wisconsin has the highest rate of infection, while Washington, as I have discussed on a number of occasions, has one of the highest total number of pertussis infections.
The Washington State Department of Health is reporting that, as of July 30 2012, there have been 3,285 cases of whooping cough (Bordetella pertussis) in the state. This compares to just 253 through the same time period in 2011. If you want to be scared, look at it graphically.