Introduction

Mumps is caused by a paramyxovirus of the Genus Rubulavirus. Mumps is principally a disease of school-age children, but approximately 15% of cases occur in adolescents or adults. It usually is self-limited, but deafness is a rare complication. Although orchitis (inflamation of the testicles) may occur in up to 20% of cases in postpubertal male patients, sterility is very rare. Naturally acquired mumps infection, including the estimated 30% of cases that occur subclinically, confers durable immunity.

It is a systemic disease characterized by swelling of the salivary glands. Approximately one third of infections, however, do not cause clinically apparent salivary gland swelling. Encephalitis occurs rarely, and permanent sequelae or death is uncommon. Orchitis is a common complication after puberty, but sterility rarely occurs. Other rare complications include arthritis, renal involvement, thyroiditis, mastitis, pancreatitis, and hearing impairment.(1)

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.(9)