SPOKANE, Wash. --- Spokane Public Schools confirmed eight cases of mumps in the district, plus three more unconfirmed but suspected cases.

Regal Elementary has two of the cases, according to Kevin Morrison, a spokesperson for Spokane Public Schools. He said that is where they are focusing their efforts, though six other schools were impacted.

Morrison said all parents of students that attend the affected schools got a phone call from their system informing them of the mumps cases. The district also sent home a letter this week or Thursday about the mumps cases.

There are a total of 31 cases of mumps in Spokane County, according to the Spokane Regional Health District (SRHD) as of Thursday afternoon. Officials confirmed the majority of the patients are 19 or younger.

Earlier this week, Mead School District confirmed they had seven students diagnosed with mumps.

RELATED: 7 Mead School District students infected with mumps

All students at SPS schools are required to be vaccinated for mumps, or present a document of exemptions.

Students can be exempt for religious, personal or medical reasons, as required by state law, according to SPS.

If there are multiple cases at one school, unvaccinated students will be told not to come to school by the health department, explained Morrison. He said SPS does not make that decision, Spokane Regional Health District does.

Morrison said only six percent of students have an exemption for any vaccination on file in the district.

Of the 31 cases in the county, health officials said at least 23 of them had gotten the measles-mumps-rubella (MMR) vaccine. They wanted to emphasize they still recommend getting vaccinated.

“The MMR vaccine is 88 percent effect at protecting against mumps so what we’re seeing is that 12 percent coming forward,” explained Kim Papich from SRHD. "Those are really good odds.”

Papich said if parents wanted to see their child’s immunization records, they should contact their pediatrician or health provider.

“No vaccine is 100 percent, so I think a lot of people falsely assume if they are vaccinated they won’t get any disease,” she said. “Eighty-eight percent is still really good coverage."

Health officials said large outbreaks are occurring across the U.S. including in Washington State. They said up to 30 percent of people with a mumps infection will have no symptoms, while others can show signs of fever, headache, tiredness, loss of appetite and swelling/ pain of the cheeks and jaw. Severe complications may include swelling of brain and tissue covering of the brain and spinal cord, deafness and swelling of testicles or ovaries.

This story has been updated.