What is measles?
Measles is an acute infection caused by the measles
virus.
Who catches measles?
Measles is now rare in the UK because of the high
levels of immunisation.
Measles is usually a childhood infection and is most
common in the 1-4 year old age group in children who
have not been immunised. However, you can catch
measles at any age.
Epidemics often coincide with school terms when
there is much more close contact between children.
How do you catch measles?
Measles is caught through direct contact with an
infected person, or through the air when he or she
coughs or sneezes.
How infectious is measles?
About 90% of people who have not been immunised or
had a past infection develop measles if they live in
the same house as someone with measles.
Measles is most infectious before the rash appears
and only trivial contact may be sufficient for the
virus to spread.
What is measles like?
Symptoms develop 9-11 days after becoming infected
and last up to 14 days from the first signs to the end
of the rash.
The first stage of measles includes irritability, a
runny nose, conjunctivitis (red eyes), a hacking cough
and an increasing fever that comes and goes. These
symptoms may last up to 8 days.
The rash starts from day 4 and the fever peaks at
around 40.6 Deg.C (105 Deg.F).
The rash
usually starts on the forehead and spreads downwards
over the face, neck and body.
The rash consists of flat red or brown blotches
which can flow into each other. It lasts 4-7 days.
There can also be diarrhoea, vomiting and abdominal
pain.
How serious is measles?
One million children die from measles world-wide
each year. In developing countries with poor
vaccination programmes measles is a more severe
disease. In the UK measles is rare. There were 4168
notified cases in 1997, but as few are confirmed many
were probably rashes due to other viruses when the
measles diagnosis was wrong.
Even in the UK, complications are quite common. They
include a severe cough and breathing difficulties
(croup), ear infections, viral and bacterial lung
infections (pneumonia), and eye infections
(conjunctivitis). Most are caused by secondary
bacterial infections which can be treated with
antibiotics.
The most serious problems involve the nervous
system. Inflammation of the brain (acute encephalitis)
occurs 2-6 days after the rash has appeared. Less than
1 in 1000 measles cases is affected in this way, but
25% of those are left with brain damage.
SSPE (subacute sclerosing pan-encephalomyelitis) is
the most severe complication of measles. It usually
occurs years after the initial illness and is a slowly
progressive brain infection. SSPE starts with
intellectual impairment and deteriorates to seizures
and eventually death. It is, however, very rare
occuring in less than 1 in 100000 cases of measles.
Measles infection during pregnancy can result in the
loss or early birth of the baby.
Severe disease and complications are most likely in
infants under 12 months, those with weakened immune
systems, the malnourished and children with vitamin A
deficiency.
Can you prevent measles?
Measles can be prevented by a highly effective
vaccine. This is part of the measles-mumps-rubella (MMR)
immunisation with a first dose at 12-15 months and a
second dose at 4-5 years.
Pregnant women or those with weakened immune systems
should not be immunised.
Past infection gives immunity.
Immunisation programmes are essential prevent
measles cases in the UK. The World Health Organisation
(WHO) has set a goal of the global eradication of
measles by 2005-2010. This needs over 95% of all
people to be immunised.
How soon should a child be back at school after
measles?
Measles is most infectious from 4 days before the
appearance of the rash until 4 days afterwards. The
DFEE and DoH guidelines on infection control in
schools and nurseries recommend that a child should be
kept off school for 5 days after the onset of the
rash.
Measles is a notifiable disease and must be reported
by a doctor to the local health authority. A saliva
test to confirm or refute the diagnosis may be
suggested.
How can you treat someone with measles?
There is no specific treatment for measles. The
patient should drink lots of clear fluid to replace
body water lost through the fever.
Paracetamol can be used to reduce the fever. Aspirin
should
NOT be given to children as its use is
associated with Reye’s Syndrome (a severe
neurological disorder).
Children with measles should be closely monitored
for complications and the doctor consulted on what
symptoms to look for.
Further Information
If you want to know more about control in
schools:
‘Guidance
on infection control in schools and nurseries’
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