Mumps

Mumps
Other names	Epidemic parotitis
Child with mumps showing characteristic facial swelling
Specialty	Infectious disease
Symptoms	Parotitis and non-specific symptoms such as fever, headache, malaise, muscle pain, and loss of appetite
Complications	Deafness, inflammatory conditions such as orchitis, oophoritis, and pancreatitis, and rarely sterility
Usual onset	7–25 days after exposure
Duration	Usually less than two weeks
Causes	Mumps virus
Risk factors	Exposure to someone with mumps
Diagnostic method	Antibody testing, viral cultures, and reverse transcription polymerase chain reaction
Prevention	Vaccination
Treatment	Supportive
Medication	Pain medication, intravenous immunoglobulin
Prognosis	Usually excellent; case fatality rate of 1.6–3.8 people per 10,000
Frequency	Most common in childhood and in countries that do not vaccinate

Mumps is a highly contagious viral disease caused by the mumps virus.^[1] Initial symptoms of mumps are non-specific and include fever, headache, malaise, muscle pain, and loss of appetite. These symptoms are usually followed by painful swelling around the side of the face (the parotid glands, called parotitis), which is the most common symptom of a mumps infection. Symptoms typically occur 16 to 18 days after exposure to the virus. About one third of people with a mumps infection do not have any symptoms (asymptomatic).

Complications are rare but include deafness and a wide range of inflammatory conditions, of which inflammation of the testes, breasts, ovaries, pancreas, meninges, and brain are the most common. Viral meningitis can occur in 1/4 of people with mumps.^[2] Testicular inflammation may result in reduced fertility and, rarely, sterility.

Humans are the only natural host of the mumps virus. The mumps virus is an RNA virus in the family Paramyxoviridae. The virus is primarily transmitted by respiratory secretions such as droplets and saliva, as well as via direct contact with an infected person. Mumps is highly contagious and spreads easily in densely populated settings. Transmission can occur from one week before the onset of symptoms to eight days after. During infection, the virus first infects the upper respiratory tract. From there, it spreads to the salivary glands and lymph nodes. Infection of the lymph nodes leads to presence of the virus in blood, which spreads the virus throughout the body. In places where mumps is common, it can be diagnosed based on clinical presentation. In places where mumps is less common, however, laboratory diagnosis using antibody testing, viral cultures, or real-time reverse transcription polymerase chain reaction may be needed.

There is no specific treatment for mumps, so treatment is supportive in nature and includes rest and pain relief. Mumps infection is usually self-limiting, coming to an end as the immune system clears the infection. Infection can be prevented with vaccination. The MMR vaccine is a safe and effective vaccine to prevent mumps infections and is used widely around the world.^[3] The MMR vaccine also protects against measles and rubella. The spread of the disease can also be prevented by isolating infected individuals.

Mumps historically has been a highly prevalent disease, commonly occurring in outbreaks in densely crowded spaces. In the absence of vaccination, infection normally occurs in childhood, most frequently at the ages of 5–9. Symptoms and complications are more common in males and more severe in adolescents and adults. Infection is most common in winter and spring in temperate climates, whereas no seasonality is observed in tropical regions. Written accounts of mumps have existed since ancient times, and the cause of mumps, the mumps virus, was discovered in 1934. By the 1970s, vaccines had been created to protect against infection, and countries that have adopted mumps vaccination have seen a near-elimination of the disease. In the 21st century, however, there has been a resurgence in the number of cases in many countries that vaccinate, primarily among adolescents and young adults, due to multiple factors such as waning vaccine immunity and opposition to vaccination.^[4]