HAGATNA, Guam — Health officials on Guam are contending with an outbreak of mumps, with more than 200 cases reported in the U.S. territory.

The Department of Public Health and Social Services said Tuesday that many of the cases involve individuals who had the recommended two doses of the measles-mumps-rubella vaccine. It says the outbreak primarily affects children 9 to 14 years old.

In response, vaccination clinics will be held to administer a third dose of the vaccine to 4th- through 8th-grade students at a number of schools.

Mumps is spread by coughing and sneezing. Common symptoms include swollen glands, with most cases involving children. It is a mild disease but sometimes can lead to complications such as hearing loss and meningitis.