A sudden illness caused by the virus paramyxovirus. It is spread by direct contact as well as by airborne droplets and saliva. Since 1967 the mumps vaccine (MMR, or measles, mumps and rubella) has helped cases decline in the United States. Symptoms include inflamed salivary glands (causing a child to have full cheeks like a chipmunk), inflamed tissues of the central nervous system (brain and spine), and an inflamed pancreas. Mumps in a child who has gone through adolescence tends to affect the ovary and the testes, which can lead to infertility.