Health officials in British Columbia are concerned about the potential spread of mumps, after 20 cases of the highly contagious virus were reported this week in the Chilliwack area.

Mumps is an infection caused by a virus that usually spreads through saliva and can infect many parts of the body, especially parotid salivary glands.

Dr. Gillian Arsenault, the Fraser Valley Regional Medical Health Officer, is working to stop the spread of mumps in B.C.
(CBC)

For that reason, young adults who haven't yet been vaccinated are thought to be particularly vulnerable to becoming infected, according to health officials.

"We are doing everything we can to vaccinate around it to stop the virus from spreading further,'' said Dr. Gillian Arsenault, the Fraser Valley Regional Medical Health Officer.

Arsenault said the public needs to be warned about mumps because one-third of those who become infected do not exhibit the usual symptoms, which include swollen cheeks or glands.

That means the actual number of cases may exceed the reported number in Chilliwack, where the outbreak is believed to have spread from Alberta.

The Chilliwack outbreak appears isolated, said Arsenault, because it involves a Christian group that doesn't believe in immunization.

But health officials are still keeping a close watch in B.C., where there are usually less than five cases of mumps reported each year.

Arsenault believes so strongly in prevention that she bought her own vaccine. Under current provincial guidelines, she is too old to get a free shot.