Vancouver Coastal Health is warning teens and young adults to ensure they are protected against the mumps as cases of the viral illness continue to swell.
The health authority says there have been 13 new cases of mumps across the region in the last month and 80 since February, well above the average of 32 illnesses annually between 2011 and 2015.
Public health officials say the latest patients range in age from 18 to 33.
As students return to high school, college or university and live in shared spaces, often with close personal contact, officials say they are at increased risk of contracting the airborne illness, which frequently causes uncomfortable swelling of salivary glands.
The health authority says mumps is spread by contact with saliva or mucus from the mouth, nose or throat of an infected person and can be transmitted by a cough, sneeze, or kissing, as well as by sharing food, drinks, or cigarettes.
Vaccination is an effective protection, but only if young people have received the correct number of doses, and public health experts say anyone who is uncertain is urged to contact the health authority for another dose, which is safe and better than being unprotected.
"We continue to see mumps in increasing numbers, and these outbreaks will continue unless young adults between the ages of 23 and 47 receive two doses of vaccine so they are fully protected," Vancouver Coastal's medical health officer Dr. Althea Hayden says in a news release.
Mumps vaccine is usually given as a shot that also protects against measles and rubella but the health authority says a second dose of that vaccine was not added to the routine schedule of childhood vaccinations until 1996.
It means many adults born between 1970 and 1995 are not fully protected, while those with birthdates between 1957 and 1969, and youths born after 1996 are considered safe.
In addition to fever and unpleasant swelling of the glands below the jaw, ears and under the tongue, mumps has the potential to cause swelling of the testes in adult males and swelling of the ovaries in adult females, although sterility is rare.
The health authority says other infrequent complications can include deafness and meningitis.
