WESTMINSTER, Colo. (CBS4) – A mumps outbreak is under investigation by the Colorado Department of Public Health and Environment.

According to information posted by Westminster Fire Department, six residents in northeast Denver and northwest Aurora have the mumps.

“It causes swelling of the salivary glands so it causes swelling of your cheeks and jaw. It’s a viral infection,” said Dr. Rachel Herlihy with Colorado Department of Public Health and Environment.

Mumps Outbreak in Denver Metro Area! Denver Public Health, Tri-County Health Department and the Colorado… https://t.co/JJSux1weS1 — Westminster FD (@WestyFire) January 27, 2017

Symptoms of the mumps, according to the Centers for Disease Control, include fever, headache, muscle aches, tiredness, loss of appetite, and swollen and tender salivary glands around the ears.

“Individuals who get mumps can have symptoms like headache, or fever, a couple of days before they start to have the swelling and can transmit during that time,” said Herlihy.

Mumps are transmitted through coughing, sneezing, sharing items like cups or eating utensils, or touching objects when touched by others with unwashed hands, and can cause a variety of complications, including inflammation in the genitals, inflammation in and around the brain, as well as deafness.

When asked if the health department expected to see more cases of the mumps in the next few days, Herlihy answered, “Because we’re actively investigating this outbreak and we’re still contacting individuals who may have been exposed, we do think there will be additional cases.”

Denver Public Health and the Tri-County Health Department are both assisting the CDPHE in the investigation.

“Individuals should be checking with their provider to see if they’re up to date on their vaccine and if their children are up to date on their vaccines,” said Herlihy.

LINK: Centers For Disease Control And Prevention Mumps Information