Health officials in Washington state said there have been 151 cases of mumps have been reported statewide since the end of October. Only 46 were reported in the four years prior. Mumps has also been reported in Oregon this year.
Mumps is a viral disease that spreads through saliva. It can affect the pancreas and cause deafness and fertility problems. Some patients who got mumps this year had received the Measles, Mumps and Rubella vaccine, better known as MMR. But that vaccination is only 88 percent effective.
“That means anybody who didn’t get vaccinated is vulnerable and a small proportion of those that did are still vulnerable as well,” Washington’s Office of Immunization spokesperson Paul Throne said.
According to Oregon’s Public Health Division, 20 cases of mumps have been reported through the second to last week of 2016. In October and November, 12 cases of mumps were reported in Marion County, south of Portland.
It’s not clear if cases in Washington and Oregon are connected to a nationwide outbreak, especially among college students. Throne said recent studies indicate the part of the MMR vaccine that covers mumps might lose its protection over time.