Mumps is a viral illness that is transmitted by direct contact with respiratory droplets or saliva from an infected person. The average incubation period for mumps is 16 to 18 days, with a range of 12 to 25 days.
Mumps outbreaks can occur any time of year. A major factor contributing to outbreaks is being in a crowded environment, such as attending the same class, playing on the same sports team, or living in a dormitory with a person who has mumps. When a person is ill with mumps, he or she should avoid contact with others from the time of diagnosis until at least 5 days after the onset of parotitis by staying home from work or school and staying in a separate room if possible.
Mumps usually involves pain, tenderness, and swelling in one or both parotid salivary glands (cheek and jaw area). Swelling first shows up in front of the lower part of the ear and then it extends downward and forwards as fluid builds up in the skin and soft tissue of the face and neck. The swollen tissue pushes the angle of the ear up and out. When the swelling worsens, the angle of the jawbone became invisible.
Other symptoms include low-grade fever, myalgia, headache, loss of appetite. There is no treatment, and symptoms usually go within a few weeks. Mumps is usually a mild disease in children, but adults may have a more serious disease with complications.
The most effective way to prevent mumps is vaccination. This vaccine is included in combination measles-mumps-rubella (MMR) and measles-mumps-rubella-varicella (MMRV) vaccines. Two doses of MMR vaccine is 88% effective in preventing mumps. It is a live virus vaccine so it is not recommended for pregnant women or patients with a weakened immune system. The MMR vaccine protects against currently circulating mumps strains.
Outbreaks can still occur in highly vaccinated U.S. communities, particularly in close-contact settings. In recent years, outbreaks have occurred in schools, colleges, and camps. This doesn’t mean that the vaccine is not effective as the effectiveness of the vaccine if assessed by comparing the attack rate in the vaccinated people with the attack rate in those who not have been vaccinated. In outbreaks in highly vaccinated population, people who have not been vaccinated against mumps usually have a much greater mumps attack rate that those who are fully vaccinated.