The Washington State Department of Health has reported 278 probable and confirmed cases of the mumps across five counties as of Wednesday.
Affected counties include King, Pierce, Snohomish, Spokane and Yakima. State health officials are urging residents to get vaccinated against the virus.
"The best protection against mumps is the [mumps, measles, rubella] vaccine," said Dave Johnson, a spokesman for the health department, according to CNN. "We are telling folks if you're sick or you think you have mumps, stay home."
The mumps are best known for painful, swollen salivary glands that cause puffy cheeks and swollen jaw. It is a highly communicable disease transmitted by person-to-person contact and is typically accompanied by initial symptoms such as fever, headache, muscle aches, tiredness and loss of appetite.
Recently, a renascent outbreak of the mumps has infected more than 2,500 people in Arkansas.
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