Mumps is a disease caused by a virus that usually spreads through saliva and can infect many parts of the body, especially the parotid salivary glands. These glands, which produce saliva for the mouth, are found toward the back of each cheek, in the area between the ear and jaw. In cases of mumps, these glands typically swell and become painful.

The virus enters the body through the airways, then passes around the body in the bloodstream. It can end up almost everywhere – the kidneys, thyroid gland, pancreas, sexual glands and, not least, the salivary gland. The virus thrives in the parotid salivary glands, which lie in the cheeks just in front of the ears.

Painful swelling of the salivary glands (classically the parotid gland) is the most typical presentation. Painful testicular swelling and rash may also occur. While symptoms are generally not severe in children, the symptoms in teenagers and adults can be more severe and complications such as infertility or subfertility are relatively common, although still rare in absolute terms. The disease is generally self-limited, running its course before waning, with no specific treatment apart from controlling the symptoms with painkillers.

You can catch mumps by being with another person who has it. There is no treatment for mumps, but the measles-mumps-rubella (MMR) vaccine can prevent it. Mumps used to be a common childhood illness. Today it is uncommon, with fewer then 1,000 cases per year on average, because of the vaccine.

Anyone who is not immune from either previous mumps infection or from vaccination can get mumps. Before the routine vaccination program was introduced in the United States, mumps was a common illness in infants, children and young adults. Because most people have now been vaccinated, mumps is now a rare disease in the United States. Of those people who do get mumps, up to half have very mild, or no symptoms, and therefore do not know they were infected with mumps.

Your odds of contracting mumps aren’t very high. Mumps was common until the mumps vaccine was licensed in 1967. Before the vaccine, up to 200,000 cases of mumps occurred each year in the United States. Since then, the number of cases has dropped dramatically.Outbreaks of mumps still occur in the United States, and mumps is still common in many parts of the world, so getting a vaccination to prevent mumps is important.

Mumps can almost always be prevented by getting a series of shots with the combination measles-mumps-rubella (MMR) vaccine. Two shots provide lifelong protection (immunity) against getting mumps: one at 12 to 15 months of age, the other at 4 to 6 years of age. There is also a measles, mumps, rubella, and varicella (MMRV) vaccine that includes a vaccine for chickenpox (varicella). This vaccine is called ProQuad and can be substituted for either or both doses of MMR.

Mumps used to be very common. Before the MMR vaccination was introduced in 1988, 87 percent of children aged up to 10 in England caught mumps and 1,200 people in England and Wales were admitted to hospital every year because of mumps. But now that the MMR vaccination is routine, mumps has become less common.

Other things people can do to prevent mumps and other infections are to wash their hands well and often with soap or an alcohol-based hand gel, and to teach children to wash their hands too. Eating utensils should not be shared and surfaces that are frequently touched should also be regularly cleaned with soap and water, or with cleaning wipes.