The outbreak began at the end of last year, when two people were reportedly infected with the disease. Of the 80 infections reported, 50 were among people who had been vaccinated for mumps, five in unvaccinated people and 25 in people whose vaccination status was not clear, the Spokane Regional Health District reported yesterday. Most of those affected are under the age of 20, according to Papich.
The health department said it expects to see more cases in the outbreak. Epidemiologists are talking to patients to see how they may have been exposed, according to Kim Papich, a spokeswoman for the Spokane Regional Health Department.
Approximately 300 students without up-to-date vaccination documents have been told to stay home in the hopes of protecting them from the virus, Papich said.
Mumps can cause swelling of the salivary glands, resulting in enlarged cheeks and jaws. Additionally it can cause fever, headache and tiredness. In rare cases it can lead to meningitis, swelling of the brain and deafness. It can also cause death.
"Mumps outbreaks can occur any time of year. A major factor contributing to outbreaks is being in a crowded environment, such as attending the same class, playing on the same sports team or living in a dormitory with a person who has mumps," the Spokane Regional Health District said on Facebook on Monday. "Also, certain behaviors that result in exchanging saliva, such as kissing or sharing utensils, cups, lipstick or cigarettes, might increase spread of the virus."
While there is a vaccine to protect against disease, usually given as part of the mumps, measles, rubella vaccine, its effectiveness can wane over time. The recommended two doses of the vaccine provide approximately 88 percent protection against infection. A single dose of the vaccine provides approximately 78 percent protection, according to the U.S. Centers for Disease Control and Prevention.
Health officials say the vaccination has been very effective, especially for those who have completed the recommended cycle.
"There's a lot of myths circulating about how mumps are spread and the efficacy of the vaccine," Papich said. "The MMR vaccine is 88 percent effective. If it wasn't doing its job, we'd see a lot more cases."