Mumps is an infection that predominantly affects children, though it can affect people at any age. It is caused by a highly contagious virus that belongs to the paramyxovirus family, but like most viral infections, it is usually a mild and self-limiting illness. The complications may be serious, however, and if parents are in any doubt about their child's well-being, they should always visit their family doctor.
INCIDENCE AND INCUBATION
Prior to the measles, mumps and rubella (MMR) vaccination programme in 1988, mumps was responsible for around 1,200 paediatric hospital admissions a year in England and Wales. Less than a decade later, the number of confirmed mumps cases had dropped to fewer than 94 cases in 1996.
From then, the number of cases rose steadily until 2005, when a sharp rise in the number of cases reached epidemic proportions. Official figures quoted 43,378 in England and Wales. Fortunately, levels have since dropped to around 4,000 mumps cases in 2010.
Epidemiologists have suggested the 2005 epidemic may have been prevented if those affected had been immunised with the MMR vaccination, which is around 95 per cent effective.
Mumps behaves like many viruses, including the common cold, in that it can be spread through the air on microscopic respiratory droplets by coughing and sneezing. It can also be transferred from one person to another through inanimate objects such as door handles and light switches. The incubation period - that is, the period of time between exposure to the virus and developing symptoms - lasts between two and four weeks.
SYMPTOMS AND COMPLICATIONS
Typically, mumps is associated with painful swollen parotid glands, so-called parotitis. The parotid glands, which help produce saliva, are located on either side of the face, at the angle of the jaw below each ear.
Mumps affects both parotid glands in the majority of cases. In addition, it causes a fever, tiredness, aching joints, headache, sore throat and mild abdominal pain.
The complications of mumps are generally more common in adults. Nevertheless, children are not immune from the potentially devastating complications that can occur.
Mumps meningitis is an infection of the meninges, the layers of tissue than cover the brain, while encephalitis is an infection of the brain itself. Meningitis causes neck stiffness, sensitivity to the light known as photophobia, and severe headache.
The type of meningitis caused by mumps is called viral meningitis, which is a very different and less serious problem than meningococcal and other forms of bacterial meningitis, which can have very serious effects.
Mumps encephalitis is less common than mumps meningitis, affecting one in every 6,000 cases of mumps. Unlike encephalitis that is caused by other viruses such as herpes, mumps encephalitis carries a low risk of death. However, neurological consequences may occur, such as damage to the nerves that supply the face, head and neck, epilepsy, and hydrocephalus. On rare occasions, mumps results in deafness.
Teenagers and adults may suffer from inflamed testicles or ovaries, which may affect fertility. Pregnant women who have not been vaccinated against mumps may suffer a miscarriage if they have been exposed to the mumps virus.
TREATMENTS
While there are treatments available against some viruses, such as the herpes virus, there is no such anti-viral agent used to treat mumps. Doctors rely on the body's immune system to fight off the infection. Usually they suggest taking over-the-counter painkillers and anti-inflamatories, having lots of rest and drinking fluids to ease the symptoms of mumps. Chewing food may be painful for the mumps sufferer and soups may be easier to swallow than solid foods.
PREVENTION
Children can spread the mumps virus for up to two days before they show any symptoms, and they may continue to be infectious for nearly a week after the symptoms have started. It is important that they remain off school or nursery until they are no longer infectious.
Good hygiene, such as hand-washing and sneezing into a tissue and subsequently throwing the tissue away, goes a long way to prevent the spread of mumps. By far the most effective way of keeping a child from catching mumps is by giving them the MMR vaccine at 13 months and the pre-school booster at around four years of age.
There is overwhelming medical evidence to demonstrate that there is no link between MMR vaccination and autism.Teachers and other adults working in the public sector should also consider having an MMR jab.
Dr Raj Thakkar BSc(Hons) MBBS MRCGP MRCP(UK) is a full-time GP in Buckinghamshire
