What is mumps?
Mumps is an illness caused by the mumps virus. Symptoms can vary from no symptoms at all, to mild respiratory infection, to acute parotitis (swelling of the salivary glands in the cheeks). Early symptoms of mumps include fever, headache, muscle aches, fatigue, and loss of appetite. Parotitis occurs in about 40% of affected individuals, and starts a few days into the illness. This is a classic sign of mumps, and generally lasts 7-10 days. The parotid swelling usually appears 16-18 days after initial exposure to the virus. This means that a person who has mumps can spread the virus around before they have any symptoms. It is recommended that patients stay at home until at least 5 days after the parotid swelling starts, to reduce the risk of transmission of mumps.
Like other viruses, mumps is spread through secretions from the respiratory tract. The virus can be contracted easily if an infected person coughs, sneezes, or even is just talking nearby. It can also be contracted by touching inanimate objects that have respiratory droplets containing the virus on them.
Mumps can cause some severe complications. In children, 1 in 20,000 cases leads to sensorineural hearing loss. Encephalitis (inflammation of the brain) occurs at an estimated incidence of 1-2 per 100,000 cases, and can cause irreversible neurologic damage. Approximately 1% of encephalitis cases are fatal. In males who are past puberty, 30-40% may get orchitis, which is painful inflammation and swelling of the testicles. Though this usually resolves on its own, it can rarely cause sterility. Mastitis (inflammation of mammary glands in the breast) has been reported in about 30% of female patients above age 15 years. Aseptic meningitis occurs in 10% of cases, and recovery is generally good. Adults are more likely than children to suffer from meningoencephalitis as a complication of mumps. Mumps during the first trimester of pregnancy increases the risk of fetal loss.
There is no specific treatment for mumps. Pain control, hydration, and rest are helpful as the body fights the illness.
How can we prevent mumps?
Mumps is a preventable disease. The mumps vaccine has been used in the United States since 1967. Prior to that, mumps was very common in the United States, with approximately 200,000 to 300,000 cases occurring each year. The vaccine has been so effective that by 2005, the two-dose series had reduced the rates of mumps by 99%. Current recommendations are for the first MMR (measles-mumps-rubella) to be given at age 12 months, and a booster shot at age 4-6 years. Having one dose of the vaccine is 78% effective at preventing mumps, and the two-dose series is 88% effective. Note that the vaccine is not 100% effective, so herd immunity (the reduction in disease occurrence due to a high percentage of the population having immunity) is important.
The most common side effect of the MMR vaccine is injection-site soreness that resolves on its own. About 10% of children may develop a fever 5-10 days after the vaccine is given. Less than 5% of children may develop a transient faint rash about 7-10 days after the vaccine. This is not contagious and goes away on its own. Children with a history of anaphylaxis to neomycin or gelatin should not receive the vaccine. Immunocompromised children or pregnant women also should not receive the vaccine. A causal relationship between MMR and autism has been disproven by multiple scientific studies, though myths continue to be perpetuated and lead to fears. Your pediatrician can help answer other questions regarding vaccine safety and benefits.
Good, frequent hand washing is also essential to help prevent the spread of mumps. Cleaning frequently touched surfaces often (door knobs, tables, etc) and not sharing utensils or cups is also important. If exhibiting symptoms of illness, it is recommended to minimize contact with others who may get ill.
What is the current mumps situation?
Mumps is no longer common in the United States, with only a few hundred people a year reported to have the disease. However, outbreaks have occurred in recent years. Outbreaks occur more commonly in the winter and spring months when people are indoors more. Outbreaks tend to occur in crowded environments, such as dormitories. There have been two outbreaks already in the United States in 2014 and a third is currently in the news. All three were in university settings. As of mid-April there were already 332 cases reported so far this year, though the number is likely to go up because of the current outbreak in Wisconsin. In 2013, 438 people were reported to have mumps nationwide.
For more information about mumps, visit the CDC website.