The estimated annual global incidence of mumps is 100-1000 cases per 100,000 population in countries without national mumps vaccination programs. In the United States, there were <300 cases in 2001 because levels of childhood vaccination are high, although occasional outbreaks—particularly among college students—continue to occur because of inadequate coverage in focal areas and waning of vaccine immunity with time.

• The incubation period of mumps is ~19 days, and humans are the only natural hosts.
• Mumps virus is transmitted by respiratory secretions and fomites. Pts are contagious from 1 week before to 1 week after symptom onset and are most contagious 1-2 days before symptom onset.