Emerging Mumps Infection.

M is one of the older described infectious diseases, first documented by Hippocrates in the fifth century BC. Before widespread use of mumps vaccines, mumps was a common disease of childhood, with nearly everyone having serologic evidence of prior infection by age 15. The virus is spread by direct contact with respiratory droplets. Salivary gland swelling, usually the parotid, is the most common physical manifestation; however, mumps virus, a paramyxovirus, can disseminate widely throughout the body, including the central nervous system, causing a wide array of medical presentations. For example, in the pre-vaccine era, mumps was the leading cause of viral encephalitis and sudden onset deafness in the United States.