Mumps

What mumps is

Mumps is caused by a paramyxovirus, a relative of the measles virus. After entering through the nose or mouth, it multiplies in the throat and lymph nodes, then spreads through the blood to glandular tissues: the salivary glands most of all, but also the testicles, ovaries, pancreas, and sometimes the brain's lining.

Before vaccination, almost every child caught mumps. Cases in the US fell by more than 99% after the vaccine was introduced in 1967. Outbreaks still happen, mainly on college campuses, in sports teams and in close-knit communities, because protection from the vaccine can wane over years.

Symptoms of mumps

Early (prodromal) symptoms

For 1 to 2 days before the swelling:

• Fever
• Headache
• Muscle aches
• Tiredness
• Loss of appetite

Parotid gland swelling

• Swelling and tenderness below and in front of the ear, pushing the earlobe up and out, and blurring the angle of the jaw
• It usually starts on one side and spreads to both within a few days, but in some people it stays on one side
• Pain on chewing or swallowing, and ear pain
• Pain made worse by sour foods or drinks such as citrus juice, which stimulate saliva
• Swelling peaks within 1 to 3 days and settles over about 1 week

The glands under the jaw and tongue can swell too. Up to about 1 in 5 infections cause no symptoms, and many others cause only a mild, cold-like illness, yet these people can still spread the virus.

Mumps in adults

Adults tend to be sicker than children and are more likely to develop complications, especially orchitis in men after puberty.

How long is mumps contagious?

The virus spreads through droplets and saliva: coughing, sneezing, talking, kissing, and sharing cups, bottles or utensils. A person is most contagious from 2 days before to 5 days after the gland swelling starts. CDC advises staying home from school, work and social activities for 5 days after the swelling begins.

How mumps is diagnosed

The pattern of fever and parotid swelling is suggestive, but many other things cause swollen glands, so a laboratory test is recommended:

• Swab of the inside of the cheek (buccal swab), ideally after massaging the parotid gland, tested by PCR. It is most accurate in the first 3 days of swelling.
• Blood test for mumps antibodies, sometimes also used. A negative result in a vaccinated person does not rule out mumps.

Mumps is a notifiable disease, so your doctor informs the local health department, which helps trace contacts and control outbreaks.

Other causes of swollen cheeks

Treatment

There is no antiviral medicine for mumps. Care focuses on comfort while the immune system clears the infection:

• Pain and fever relief: acetaminophen (paracetamol) or ibuprofen, following the label dose. Do not give aspirin to children or teenagers.
• Fluids: plenty of water. Avoid acidic drinks such as orange juice and lemonade.
• Soft foods that need little chewing: soups, yogurt, mashed potatoes, scrambled eggs.
• Warm or cold compresses on the swollen glands.
• Rest and stay away from others for 5 days after swelling starts.
• For swollen testicles: supportive underwear or a scrotal support, cold packs wrapped in cloth and pain relief.

Complications of mumps

Most complications are more common in adults and in unvaccinated people.

• Orchitis: painful testicular swelling, usually a week after the parotid swelling. It affects up to about 30% of unvaccinated males after puberty, and far fewer vaccinated males. It usually affects one side. Some shrinkage of the testicle follows in a share of cases, but infertility is rare. See orchitis.
• Oophoritis and mastitis: inflammation of the ovaries or breasts in women.
• Viral meningitis: headache, stiff neck and light sensitivity; usually recovers fully.
• Encephalitis: brain inflammation; rare but serious.
• Hearing loss: sudden, usually in one ear, and sometimes permanent. Rare.
• Pancreatitis: upper belly pain and vomiting.
• Pregnancy: mumps in the first trimester may slightly raise the risk of miscarriage; it is not known to cause birth defects.

Prevention: the MMR vaccine

The measles, mumps and rubella (MMR) vaccine is the best protection:

• Children: first dose at 12 to 15 months, second at 4 to 6 years.
• Adults born in 1957 or later without evidence of immunity: at least 1 dose; 2 doses for college students, health care workers and international travelers.
• During outbreaks: health departments may recommend a third dose for people in the affected group.

Two doses are about 88% effective against mumps and greatly reduce the risk of complications in those who still get infected. The MMR vaccine is not given during pregnancy.

Other measures: wash hands often, do not share drinks or utensils, cover coughs and sneezes, and keep sick people home for 5 days.

Outlook

Most people recover completely within about 2 weeks. Lifelong immunity usually follows natural infection, though rare second infections have been reported. Permanent problems such as hearing loss or reduced fertility are uncommon.

Frequently asked questions

What are the first signs of mumps?

The first signs are usually fever, headache, muscle aches, tiredness and loss of appetite. One to two days later, a tender swelling develops below and in front of one or both ears, making the cheeks and jaw look puffy. Some people never develop obvious swelling.

How long is mumps contagious?

Mumps spreads most easily from about 2 days before the glands swell until 5 days after. Health authorities advise staying home from school, work and gatherings for 5 days after swelling begins. People without symptoms can still spread the virus.

Can you get mumps if you have been vaccinated?

Yes, but it is less likely and usually milder. Two doses of MMR are about 88% effective. Protection can fade over time, and outbreaks in close-contact settings like colleges can include vaccinated people. Their risk of complications such as orchitis and meningitis is much lower.

How long does mumps last?

The illness usually lasts about 10 days to 2 weeks. Gland swelling peaks in 1 to 3 days and fades over about a week. Complications such as orchitis can extend recovery by a further week or two.

Can mumps make you infertile?

Rarely. Mumps orchitis can shrink the affected testicle and lower sperm count, but it usually affects only one side, and complete infertility is uncommon. Women may develop ovarian inflammation, which is not thought to cause infertility in most cases.