But mumps can also cause more serious illness. It can cause deafness. Occasionally the disease also causes encephalitis, which is inflammation of the brain itself. Usually, the child recovers without permanent damage. About 1 out of every 4 teenage or adult men who get mumps develops a painful swelling of the testicles.
People get mumps through contact with others who are already infected.
It can be spread by coughing, sneezing, or simply talking. Before a vaccine was available, nearly every child got mumps. Now the number of cases is much lower. However, children who are not immunized are still very likely to get the disease. You can read about mumps, measles, and rubella vaccines here.