Mumps is caused by a virus.
Mumps spreads from person to person through the air. It is less contagious than measles or chickenpox.
The incubation period of mumps is 14-18 days, but can range from 14-25 days.
Individuals with mumps usually first feel sick with such nonspecific symptoms as headache, loss of appetite, and low-grade fever.
The most well-known sign of mumps is "parotitis," the swelling of the salivary glands, or parotid glands, below the ear. Parotitis occurs only in 30%-40% of individuals infected with mumps.
Up to 20% of persons with mumps have no symptoms of disease, and another 40%-50% have only nonspecific or respiratory symptoms.
In children, mumps is usually a mild disease. Adults may have more serious disease and more complications.
Central nervous system involvement (meningitis) is common, but is usually not serious. Meningitis (with headache, stiff neck) occurs in up to 15% of people with mumps, but usually resolves without any permanent damage. Up to 50% of postpubertal males experience "orchitis," or testicular inflammation, as a complication of mumps. This may involve pain, swelling, nausea, vomiting, and fever, with tenderness of the area possibly lasting for weeks. Sterility is a rare complication, however.
An increase in spontaneous abortion (miscarriage) has been found among women who developed mumps during the first trimester of pregnancy; however, there is no evidence that mumps causes birth defects. Deafness, in one or both ears, can occur in approximately one per 20,000 reported cases of mumps.
There is no "cure" for mumps, only supportive treatment (bed rest, fluids, and fever reduction).
Mumps is diagnosed by a combination of symptoms and physical signs and laboratory confirmation of the virus, as not all cases develop characteristic parotitis and not all cases of parotitis are caused by mumps.
The infectious period is considered to be three days before symptoms begin to the ninth day following the onset of symptoms.
If your child has not been vaccinated against mumps, receiving the vaccine after exposure to the virus will not help prevent disease if the child has already been infected. However, if the child did not become infected after this particular exposure, the vaccine will help protect him or her against future exposure to mumps.
Due to good immunization coverage, mumps is now rare in the United States. An estimated 212,000 cases occurred in 1964, while only 258 cases were reported in 2004. In 2006, outbreaks of mumps occurred in 45 states and the District of Columbia, primarily on college campuses. During January 1-October 7, 2006, 5,783 confirmed or probable cases of mumps were reported to CDC.
The currently used mumps vaccine was licensed in 1967.
The mumps vaccine is made from a live attenuated (weakened) virus. In the United States, it is recommended that it be given as part of the MMR vaccine, which protects against measles, mumps, and rubella (German measles) or the MMRV vaccine (MMR plus varicella (chickenpox) vaccine) when age-appropriate (licensed for use only from age 12 months through age 12 years).
This vaccine is given by subcutaneous injection, meaning that the vaccine is deposited just under the skin and not deep into the muscle.
At least one dose of mumps-containing vaccine is routinely recommended for all children and for all persons born during or after 1957. In the United States, mumps vaccine is given as part of the combination vaccines MMR or MMRV (when age-appropriate). Two doses of MMR/MMRV are recommended for all children and certain adults at risk of measles or mumps exposure.
The first dose of MMR or MMRV should be given on or after the first birthday; the recommended range is from age 12-15 months. A dose given before 12 months of age may not be counted, so the child's medical appointment should be scheduled with this in mind.
The second dose of MMR is usually given when the child is 4-6 years old, or before he or she enters kindergarten or first grade. However, the second dose of MMR can be given anytime as long as it is at least four weeks after the first dose. MMRV can only be given through age 12 years and should be separated from a previous dose of varicella-containing vaccine by 12 weeks.
The Centers for Disease Control and Prevention (CDC), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP) have all recommended this vaccine.
Mumps is a very safe vaccine. Most side effects are mild and related to the measles or rubella components of the MMR vaccine (fever, rash, temporary joint symptoms).
Fever is the most common side effect, occurring in 5%-15% of vaccine recipients. About 5% of persons develop a mild rash. When they occur, fever and rash appear 7-10 days after vaccination. About 25% of adult women receiving MMR vaccine develop temporary joint pain, although this symptom is related to the rubella component of the combined vaccine. Joint pain only occurs in women who are not immune to rubella at the time of vaccination. MMR vaccine may cause thrombocytopenia (low platelet count) at the rate of about 1 case per 30,000-40,000 vaccinated people. Cases are almost always temporary and benign.
More severe reactions, including allergic reactions, are rare. About one person per million develops inflammation of the brain, which is probably caused by the measles vaccine virus.
Approximately 95% of individuals become immune to mumps after a single dose of vaccine. The second dose of MMR vaccine is intended to produce immunity in the 5% of persons who did not respond to the first dose. This also ensures that the individual gets another chance to become immune to measles and rubella.
Anyone who experiences a severe allergic reaction (e.g., hives, swelling of the mouth or throat, difficulty breathing) following the first dose of MMR should not receive a second dose. Anyone knowing they are allergic to an MMR component (gelatin, neomycin) should not receive this vaccine.
Pregnant women should not receive the MMR vaccine, and pregnancy should be avoided for four weeks following vaccination with MMR. While there is no evidence that the mumps vaccine causes fetal damage, women are advised not to receive the MMR vaccine during pregnancy as a safety precaution based on the theoretical possibility of a live vaccine causing disease.
Severely immunocompromised persons should not be given MMR vaccine. This includes persons with a variety of conditions, including congenital immunodeficiency, AIDS, leukemia, lymphoma, generalized malignancy, or those undergoing immunosuppressive therapy.
In the past it was believed that persons who were allergic to eggs would be at risk of an allergic reaction from the vaccine because the vaccine is grown in tissue from chick embryos. However, recent studies have shown that this is not the case. Therefore, MMR may be given to egg-allergic individuals without prior testing or use of special precautions.
Persons are generally considered to be immune to mumps if they were born before 1957, have laboratory evidence of mumps immunity, have documentation from their health professional of previous mumps disease, or have received appropriate mumps vaccination.
There is no scientific evidence that measles, MMR, or any other vaccine causes autism. The question about a possible link between MMR vaccine and autism has been extensively reviewed by independent groups of experts in the U.S. including the National Academy of Sciences' Institute of Medicine. These reviews have concluded that the available epidemiologic evidence does not support a causal link between MMR vaccine and autism.
The MMR-autism theory had its origins in research by Andrew Wakefield and colleagues in England. They suggested that inflammatory bowel disease (IBD) is linked to persistent viral infection. In 1993, Wakefield and colleagues reported isolating measles virus in the intestinal tissue of persons with IBD. The validity of this finding was later called into question when it could not be reproduced by other researchers. In addition, the findings were further discredited when an investigation found that Wakefield did not disclose he was being funded for his research by lawyers seeking evidence to use against vaccine manufacturers.
The studies that suggest a cause-and-effect relationship exists between MMR vaccine and autism have received a lot of attention by the media. However, these studies have significant weaknesses and are far outweighed by many population studies that have consistently failed to show a causal relationship between MMR vaccine and autism.
Reprinted from: Immunization Action Coalition