Mumps on the Rise

Last Wednesday Reuters reported on the spread of mumps to eight midwestern states and 1100 cases:

The outbreak is the largest mumps epidemic in the United States in more than 20 years, the U.S. Centers for Disease Control and Prevention said.
Most are in Iowa, where 815 cases have been recorded, the CDC said.
An additional 350 mumps cases have been reported in Minnesota, Kansas, Illinois, Nebraska, Wisconsin, Missouri and Oklahoma, officials said. Investigators are reviewing possible cases in seven other states that were not named.