Measles
Introduction
Measles (sometimes known as morbilli) is a highly infectious viral illness. It causes a range of symptoms including fever, coughing and distinctive red-brown spots on the skin.
The measles virus is contained in the millions of tiny droplets that come out of the nose and mouth when an infected person coughs or sneezes.
You can catch measles by breathing in these droplets or, if the droplets have settled on a surface, by touching the surface and then placing your hands near your nose or mouth.
The most effective way of preventing measles is the measles, mumps and rubella (MMR) vaccine.
How common is measles?
The success of the MMR vaccine means that in the UK, cases of measles are rare. However, in recent years the number of cases has been increasing. For example, in 2009 there were 1,143 cases of measles in England and Wales compared with 70 cases in 2001.
It is thought that the rise in the number of cases of measles is due to parents not getting their child vaccinated with the MMR vaccine. This is probably due to speculation linking MMR to autism.
Publicity in 1998 highlighted a report claiming a link between the MMR jab and autism. However, numerous studies that were undertaken to investigate this claim found no link between the MMR vaccine and autism.
Who is affected?
Measles is most common among children aged 1-4 years old, although anyone who has not been vaccinated against measles can catch it.
Outlook
Treatment for measles is normally not necessary as the body's immune system can usually fight off infection in a couple of weeks. Typically, once you have fought off the measles infection, you develop immunity (resistance) to it.
However, possible complications of measles include pneumonia, ear and eye infections and croup (an infection of the lungs and throat).
More serious complications, such as inflammation of the brain (encephalitis), are rarer but can be fatal. There are hundreds of thousands of deaths worldwide from measles every year.
Measles and pregnancy
If you are planning to get pregnant and you have not had measles, arrange with your GP to have the MMR vaccine. If you catch measles during pregnancy, it can be passed on to your baby, which can be very damaging or even fatal to your baby. Measles in pregnancy can cause miscarriage, premature labour or a baby with low birth weight. The MMR jab cannot be given during pregnancy.
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Symptoms
Around 9-11 days after you get the measles infection, the following symptoms begin to appear:
- cold-like symptoms, such as runny nose, watery eyes, swollen eyelids, and sneezing,
- red eyes and sensitivity to light,
- a mild to severe temperature, which may peak over 40.6C (105F) for several days, then fall but go up again when the rash appears,
- tiny greyish-white spots (called Koplik's spots) in the mouth and throat,
- tiredness, irritability and general lack of energy,
- aches and pains,
- poor appetite,
- dry cough,
- red-brown spotty rash (see below).
The above symptoms generally last for up to 14 days.
Rash
The measles rash appears 3-4 days after initial symptoms and last for up to 8 days. The spots usually start behind the ears, spread around the head and neck, then spread to the legs and the rest of the body.
The spots are initially small but quickly get bigger and often join together. Similar-looking rashes may be mistaken for measles, but measles has a range of symptoms, not just a rash.
Most childhood rashes are not measles but you should consult your GP without delay if:
- you suspect it is measles,
- symptoms worsen,
- temperature increases to above 38°C (100.4°F),
- temperature stays high after other symptoms have gone, or
- there are signs of other related illnesses (see Complications).
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Causes
Measles is caused by infection with the rubeola virus. This virus is contained in the millions of tiny droplets that come out of the nose and mouth when someone with measles coughs or sneezes.
You can catch measles by breathing in these droplets or, if the droplets have settled on a surface, by touching the surface and then placing your hands near your nose or mouth. The measles virus can survive on surfaces for a few hours.
Once inside your body, the virus multiplies in the back of your throat and lungs before spreading throughout your body, including your respiratory system and the skin.
Someone with measles is infectious for two to four days before the rash appears and for about five days after it appears.
Immunity
Anyone who has not had measles before can be infected. However, cases of reinfection, after you have had the virus, are extremely rare because the body builds up immunity (resistance) to the virus.
Most people who are not immune from measles and are sharing a house with somebody who is infected will develop the condition.
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Diagnosis
Your GP will usually be able to diagnose measles from the combination of symptoms, such as the characteristic rash and the small spots inside the mouth.
A simple blood test or saliva test can confirm a diagnosis and identify the rubeola virus.
Doctors have a duty to notify the local authority of all reported and suspected cases of measles. They will also notify the child’s school if necessary.
Your child should not return to school until at least five days after the appearance of the rash.
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Treatment
There is no specific treatment for measles. Once the rash starts, you will need to rest and treat the symptoms until your immune system fights off the virus. If there are no complications, symptoms usually disappear in 7-10 days.
If your child has measles, you may find the following advice useful:
- Use liquid baby paracetamol or ibuprofen to relieve fever, aches and pains. Do not give aspirin to children under the age of 16.
- Closing curtains or dimming lights can help reduce light sensitivity.
- Damp cotton wool can be used to clean away any crustiness around the eyes. Use one piece of cotton wool per wipe for each eye. Gently clean the eye from inner to outer lid.
- Cough medicines are of little help and should not be given to children under the age of six. Children over 12 months old may benefit from a teaspoon of lemon juice and two teaspoons of honey in a glass of warm water. Honey should not be given to babies under the age of 12 months.
- Placing a bowl of water in the room will make the atmosphere more humid, which can help relieve a cough.
- Feverish small children rapidly lose water, which makes a cough worse. Children should drink as much as possible to prevent dehydration.
While antibiotics are of no use to treat the virus, they may be prescribed for any secondary bacterial infections that develop .
In severe cases of measles, particularly when there are more serious complications, hospital treatment may be required.
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Complications
Complications resulting from measles are more likely to develop in certain children, for example:
- children with a weakened immune system, such as those with leukaemia or AIDS,
- children with a poor diet, and
- children under the age of five.
Complications are also more likely to develop in adults who are over the age of 20.
Common complications
Some of the common complications of measles are:
- diarrhoea,
- vomiting,
- eye infection (conjunctivits), and
- inflammation of the voicebox (laryngitis).
Inner ear infection and inflammation (otitis media), which often causes earache, may also be a complication of measles.
Fits that are caused by a fever (febrile convulsions) are also possible complications of measles. However, the fits, although alarming, are not usually dangerous.
Less common complications
Less common complications of measles are:
- meningitis,
- pneumonia (lung infection), signs of which are fast, difficult breathing, chest pain and deteriorating condition,
- hepatitis (liver infection),
- encephalitis (inflammation of the brain), which can be fatal, so watch for drowsiness, headache, and vomiting,
- low platelet (white blood cell) count, known medically as thrombocytopenia, which affects the blood's ability to clot,
- bronchitis and croup (infection of the airways), characterised by a hacking or barking cough, and
- squint, if virus affects the nerves and muscles of the eye.
Rare complications
In rare cases, measles can lead to the following conditions:
- Serious eye disorders, such as an infection of the optic nerve (the nerve that transmits information from the eye to the brain), known as optic neuritis, which can lead to blindness,
- heart and nervous system problems,
- a serious brain complication known as subacute sclerosing panencephalitis (SSPE), which can sometimes occur several years after measles. Although the condition is fatal, it is very rare, occurring in only 1 in every 100,000 cases of measles.
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Prevention
If you think that your child may have the measles, keep them away from other children for at least five days until after the rash has appeared.
Vaccinated children and anyone who has already had measles are extremely unlikely to catch measles.
MMR vaccination
The first MMR vaccination should be given to all children at around 13 months of age. A booster dose is given before they start school (when they are 3 to 5 years old). Between 5% and 10% of children are not fully immune after the first dose, so the booster jab helps to increase protection. Less than 1% of children remain at risk after the booster.
If a child younger than 13 months of age is exposed to the measles virus, the action taken to prevent them developing the disease will depend on whether they are under or over six months of age.
Children who are aged 6-13 months
A child aged between 6 and 13 months who is exposed to the measles virus will normally be given the MMR vaccine to protect them. However, if a child is given the vaccine before their first birthday, they should still be given two further doses as part of the childhood immunisation programme. These doses should be given at around 13 months of age and before the child begins school.
Children aged under six months
If the child’s mother has had measles in the past, the child will usually be immune to measles infection because the mother’s protective antibodies will have passed to the baby in the womb.
However, if the mother has not had measles, the child may be given an injection of human normal immunoglobulin (HNIG). HNIG is not a vaccine. It is a special concentration of antibodies which can give short-term but immediate protection against measles.
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