Measles is a highly infectious illness caused by a virus. The virus lives in the mucus of the nose and throat of people with this infection. Physical contact, coughing and sneezing can spread the infection. In addition, infected droplets of mucus can remain active and can be passed on by touching (they are contagious) for around two hours. This means that the virus can live outside the body – for example, on surfaces and door handles. Worldwide, measles is the leading cause of vaccine-preventable death.
Symptoms of Measles
Once you are infected with the virus, the virus multiples in the back of your throat and in your lungs. It then spreads throughout your body. The following are the most common symptoms of measles:
- A high temperature (fever), sore eyes (conjunctivitis) and a runny nose usually occur first.
- Small white spots usually develop inside the mouth a day or so later. These can persist for several days.
- A harsh dry cough is usual.
- Going off food, tiredness and aches and pains are usual.
- Diarrhoea and/or being sick (vomiting) is common.
- A red blotchy rash normally develops about 3-4 days after the first symptoms. It usually starts on the head and neck and spreads down the body. It takes 2-3 days to cover most of the body. The rash often turns a brownish colour and gradually fades over a few days.
Children are usually quite unwell and miserable for 3-5 days. After this, the fever tends to ease and then the rash fades. The other symptoms gradually ease and go.
Most children are better within 7-10 days. An irritating cough may persist for several days after other symptoms have gone. The immune system makes antibodies during the infection. These fight off the virus and then provide lifelong immunity. It is therefore rare to have more than one bout of measles.
Some people mistake rashes caused by other viruses for measles. Measles is not just a mild red rash that soon goes. The measles virus causes an unpleasant and sometimes serious illness. The rash is just one part of this illness.
Diagnosis of measles
The doctor will usually be able to diagnose measles from the combination of symptoms, especially the characteristic rash and the small spots inside the mouth. However, a simple blood or saliva test can be usually done to confirm the diagnosis.
Complications of measles
Complications are more likely in children with a poor immune system (such as those with leukaemia or HIV), those who are malnourished, children aged under 5 years and adults. Many malnourished children in the world die when they get measles, usually from a secondary lung infection (pneumonia). These children have usually not been immunised.
More common complications include:
- Eye infection (conjunctivitis).
- Inflammation of the voice box (laryngitis).
- Ear infection causing earache.
- Infections of the airways, such as bronchitis and croup, which can be common.
Although these are distressing, they are not usually serious. Less common complications of measles are listed below:
- A febrile fit (convulsion) occurs in about 1 in 200 cases. This can be alarming,but full recovery is usual.
- Brain inflammation (encephalitis). This is a rare but very serious complication. It occurs in about 1 in 5,000 cases. It typically causes drowsiness, headache and being sick (vomiting) which start about 7-10 days after the onset of the rash. Encephalitis may cause brain damage. Some children die from this complication.
- Liver infection (hepatitis).
- This is a serious complication that sometimes develops. Typical symptoms include fast or difficult breathing, chest pains and generally becoming more ill.
- Squint is more common in children who have had measles. The virus may affect the nerve or muscles to the eye.
Treatments for measles
There is no specific medicine that kills the measles virus. Treatment aims to ease symptoms until the body’s immune system clears the infection. For most cases, rest and simple measures to reduce a high temperature (fever) are all that are needed for a full recovery. Symptoms will usually disappear within 7-10 days.
The following measures are often useful:
- Children should drink as much as possible to prevent lack of fluid in the body (dehydration). Ice lollies are a useful way of giving extra fluid and keeping cool.
- Paracetamol or ibuprofen can be taken to ease fever and aches and pains. The child should be kept cool (but not cold).
- Antibiotics do not kill the measles virus and so are not normally given. They may be prescribed if a complication develops, such as a secondary bacterial ear infection or secondary bacterial lung infection (pneumonia).
- Cough remedies have little benefit on any coughs.
- Vitamin A supplements have been shown to help prevent serious complications arising from a measles infection. Supplements are generally recommended for children living in a country with a high prevalence of a vitamin A deficiency. Vitamin A is a proven effective intervention to prevent measles mortality in children.
Immunisation is routine as part of the measles, mumps and rubella (MMR) vaccine. Two doses are usual – the first for children aged between 12 and 13 months and the second usually given at age 3 years and 4 months to 5 years. Immunisation gives excellent protection. Measles immunisation can be given at any age and is sometimes offered to older children during outbreaks.
Measles is one of the most contagious infectious diseases. It is passed on by coughing and sneezing the virus into the air. It takes between 7 and 18 days (most commonly 10-12 days) to develop symptoms after being infected. (This is the incubation period.). A patient is infectious and can pass it on to others from four days before to four days after the onset of the rash. Therefore, patients with measles should not mix with others to limit the spread of the disease.
If an unimmunized person who comes into contact with someone with measles should see a doctor and if necessary, immediate immunisation may be advised.