Officials with the Delaware Division of Public Health say the mumps are spreading in Delaware.
Last week DPH announced three mumps cases. Each involved people who attended a Baile Mejicano dance event at the Chase Center on the Riverfront in Wilmington.
The number of cases has now reached nine, and most are associated with the event on February 10, or a similar dance which took place on March 3.
DPH recommends all who attended these events, and those who live with them, to see their primary care physician.
The mumps is contracted through saliva and can lead to complications in adults including serious inflammatory issues. The Centers for Disease Control and Prevention note an increase in mumps cases nationwide dating back to 2015.