Seattle-King County Public Health is investigating an outbreak of the mumps.
Three children in Auburn were diagnosed with the infection, and officials confirmed a fourth case Tuesday night. Public Health is investigating at least 10 additional cases.
The three confirmed Auburn cases are from the same family, between the ages of eight to 13 years old. In the other 11 cases, seven are children.
Mumps is caused by a virus and can cause fever, headache, and swelling of the cheeks and jaw. Most people recover from the illness within a few weeks. It is spread through coughing, sneezing, spraying saliva, or touching surfaces shared with an infected person.
Mumps can be prevented by staying up-to-date on MMR vaccinations, washing hands frequently, and avoiding shared drinks and utensils.
However, a spokesperson for King County Public Health said the vaccination is effective, but not perfect. All four people with confirmed cases were vaccinated.
"People who have received two doses of the MMR vaccine are about nine times less likely to get mumps than unvaccinated people who have the same exposure to mumps virus," James Apa, a department spokesperson, wrote in an email. "However, some people who receive two doses of MMR can still get mumps, especially if they have prolonged, close contact with someone who has the disease."