Mumps is a mild childhood infection most commonly affecting children aged 5 to 9 years. It is caused by the mumps virus and is transmitted from person to person through direct contact or respiratory droplets. Individuals with mumps are contagious from 2 days before to 9 days after the onset of parotid swelling. The illness typically begins with fever, malaise, headache, and the characteristic parotid gland swelling. 

While mumps is often uncomplicated in children, adults are at higher risk of complications including meningitis, orchitis, and hearing loss. Orchitis occurs in approximately 20% of post-pubertal males with mumps, and both testes are affected in about 20% of these cases; however, mumps orchitis rarely results in permanent infertility. Acquisition of mumps during the first 12 weeks of pregnancy is associated with a 25% risk of spontaneous abortions, but fetal malformations following maternal mumps infection have not been reported.