infectious illness caused by a virus - a viral infection caused by the rubeola virus.
Measles is an endemic disease; meaning it is continually present in a community and many people develop resistance. If
measles enters an area where the people have never been exposed the result can be devastating.
A measles outbreak in 1592 in the island of Cuba killed
approximately two-thirds of the native population who had
previously survived smallpox. A couple of years later half the
indigenous population of Honduras died.
Over the last 150 years, estimates place the total global measles death toll at 200 million people. One fifth of Hawaii's population died in the 1850s from measles.
Scientists have identified 21 different strains of the measles
virus.
Symptoms of measles
Measles symptoms invariably include fever, together with at
least one of the three C's (cough, coryza, conjunctivitis). Symptoms will appear about 9-11 days after infection.
Measles symptoms may include the following:
Coryza - runny nose.
Dry hacking cough.
Conjunctivitis - swollen eyelids, inflamed eyes.
Watery eyes.
Photophobia - sensitivity to light.
Sneezing.
Fever - this may be mild to severe and can reach 105F (40.6C) for a number of days. Fever may drop, and then rise again when the rash appears.
Koplik's spots - very small grayish-white spots with
bluish-white centers in the mouth, insides of cheeks, and
throat.
Aches generally all over the body.
Rash - 3 to 4 days after initial symptoms a reddish-brown spotty rash appears. The rash can last for over a week. It usually starts behind the ears and spreads all over the head and neck. After a couple of days it spreads to the rest of the body, including the legs. As the little spots grow many of them will join together.
Although the majority of childhood rashes are not measles, you should take your child to the doctor if:
You suspect it could be measles.
Symptoms do not improve, or get worse.
The fever rises to above 38C (100F).
When the symptoms have gone, but the fever hasn't.
What causes measles?
Measles is caused by infection with the rubeola virus, a
paramyxovirus of the genus Morbillivirus. The virus lives in the mucus of the nose and throat of an infected child or adult.
The infected person is contagious for four days before the rash appears, and continues so for about four to five days
afterwards. You can become infected through:
Physical contact with an infected person.
Being nearby infected people if they cough or sneeze.
Touching a surface that has infected droplets of mucus
(the virus remains active for two hours) and then putting
your fingers into your mouth, rubbing your nose or eyes.
How does a measles infection develop in a person?
As soon as it enters the body the virus multiplies in the back of the throat, lungs and the lymphatic system. It later infects and replicates in the urinary tract, eyes, blood vessels and central nervous system.
Scientists at the Mayo Clinic say that replication in the airways is not required. They found that a virus replicating only in immune cells causes measles in monkeys.
Experts say it takes from 1 to 3 weeks for the virus to establish
itself. However people show symptoms 9-11 days after
infection.
A person who has had measles before does not become infected again; cases of re-infection are very rare. However, anyone who has never been infected and has not been vaccinated and breathes in infected droplets, or is in close physical contact with an infected person is likely to become ill.
Approximately 90% of people who share a house with an infected person and have no immunity develop measles.
How is measles diagnosed?
A GP (general practitioner, primary care physician) will be able to diagnose measles fairly easily if the signs and symptoms are present. A blood test will confirm the presence of the rubeola virus.
In most countries measles is a notifiable disease. This means
that doctors have to notify the authorities of any suspected
cases. If the patient is a child the doctor will also notify the
school.
A child with measles should not return to school until at least
five days after the rash has appeared.
Treatments for measles
There is no specific measles treatment. If there are no
complications the doctor will recommend plenty of rest and
normal measures to control the fever and prevent dehydration
(drink fluids). Symptoms will usually go away within 7 to 10
days.
If your child has measles, the following measures may help:
Fever - if the temperature is high try to keep the child cool, but make sure he/she is not cold. Tylenol (paracetamol, acetaminophen) or ibuprofen are effective in controlling fever, as well as aches and pain. Children under 16 should not be given aspirin. Check with your
doctor about acetaminophen dosage - too much can harm the child, especially the liver.
Smoking - do not let anyone smoke near the child with
measles.
Photophobia - as the child may be painfully sensitive to light, keeping the lights dim or the room darkened may help. Sunglasses may also help.
Conjunctivitis - if there is crustiness around the eyes
gently clean with damp cotton wool.
Cough - cough medicines will not relieve the cough. Making the room more humid by placing a bowl of water may help the cough. If the child is over twelve a glass of warm water with a teaspoon of lemon juice and two teaspoons of honey may help. Do not give honey to
babies.
Dehydration - make sure the child is hydrated. If the child has a fever he/she can become dehydrated more quickly. Encourage the child to drink plenty of fluids.
Isolation - while children are contagious they should be kept away from school and should not return to activities that involve human interaction. Non-immunized people who have never had measles should be kept out of the house.
Vitamin A supplements - studies have shown that Vitamin A supplements significantly help prevent complications caused by measles. Supplements are
recommended for children with vitamin A deficiency and children under the age of two who have severe measles. Vitamin A deficiency is virtually non-existent in developed countries, but fairly common in much of the
developing world.
As measles is caused by a virus antibiotics will not have any
effect on it. However, sometimes antibiotics may be prescribed for any infections that may develop.
Complications of measles
Complications from measles are fairly common, and are more
likely to get worse for patients who have weak immune systems, such as those with HIV/AIDS or leukemia, those with vitamin deficiency, and very young children. Adults over the age of 20 are more likely to have complications than healthy
children over the age of 5.
About 20% of people who develop measles have some kind of
complication, which may include:
Diarrhea.
Vomiting.
Eye infection.
Laryngitis and bronchitis - laryngitis is inflammation of the voice box. Bronchitis is inflammation of the inner walls that line the main air passageways. About 4% of people with measles have difficulties breathing.
Otitis media - inner ear infection and inflammation.
Febrile convulsion - fits caused by fever. Occurs in 1 in 200 cases. May be alarming, but children usually make a full recovery.
Pneumonia - patients with weakened immune system who develop measles are vulnerable to an especially dangerous type of pneumonia (Streptococcus
pneumoniae) which can be fatal.
The following less common complications are also possible:
Hepatitis - liver complications in childhood measles is rare and temporary. However, it can be severe in children receiving hepatotoxic drugs (medications which may be toxic to the liver). Acetaminophen (Tylenol, paracetamol) can harm the liver if the dose is too high. Check
acetaminophen dosage with your doctor if you wish to use it to treat fever.
Encephalitis - approximately 1 in every 1,000 patients with measles develops encephalitis. This is an inflammation of the brain which may cause vomiting, and convulsions. Coma and even death is possible, but rare.
Encephalitis may occur soon after measles, or several years later.
Thrombocytopenia - low platelet count. The blood's ability to clot is affected. The patient may bruise easily.
Squint - eye nerves and eye muscles may be affected.
The complications listed below are very rare, but possible:
Neuritis - infection of the optic nerve, which can lead to
blindness.
Heart complications
Subacute sclerosing panencephalitis (SSPE) - Occurs
in 1 in every 100,000 cases. SSPE is a brain disease which can occur several months or years after measles infection and causes convulsions, motor abnormalities, mental retardation and death.
Other nervous system complications - toxic
encephalopathy, retrobulbar neuritis, transverse myelitis,
and ascending mielitis.
Pregnancy
Measles during pregnancy can cause miscarriage, premature
labor, or low birth weights. If you are planning to get pregnant
and have not been vaccinated against measles talk to your
doctor about getting the MMR jab.
Prevention of measles
People who have already had measles are immune and will not
get it again - cases of re-infection are extremely rare. If you were born or living in the USA before 1957 you will be
immune, experts say. For people who are not immune there is the measles vaccine.
Vaccination
Before vaccination became available in the 1960s
approximately 400 to 500 people died each year from measles in the USA. There are no reliable statistics on the number of
complications which led to permanent disabilities, such as brain damage or blindness that occurred before the measles vaccine became available.
The World Health Organization (WHO) says that nearly 600
million children received the measles vaccine between 2000 and
2007, resulting in a 74% drop in global deaths caused by measles - and a drop of about 90% in the eastern Mediterranean and Africa regions. Measles deaths in Africa fell by 91 percent between 2000 and 2006, from an estimated 396,000 to 36,000, thanks to The Measles Initiative.
Unfortunately, due to political and religious disagreements,
vaccination rates in Nigeria dropped dramatically two years
after the program started, resulting in a significant rise in infections and hundreds of childhood deaths.
In 2000 an estimated 750,000 people died from measles
globally, most of them children. By 2007 the annual number of
deaths dropped to 197,000 thanks to a concerted effort to
vaccinate children in Africa and other hard-hit regions, the
World Health Organization reported.
Herd immunity protects people who cannot take the vaccine
Before measles vaccines became available over 3 million people
in the USA became infected with measles each year. By the year 2000 the Centers for Disease Control and Prevention (CDC) declared that measles had been eliminated from the country.
For people who cannot take the vaccine because of certain
medical conditions this was great news, because they had herd immunity. Their risk of becoming infected, even though they had not received the vaccine, was significantly low because so few people in the community - in the herd -carried the virus.
Unfortunately, this herd immunity has weakened slightly. 2014 saw a big increase in the number of measles cases - 644 over 27 US states. In a spotlight article in February 2015, we discussed whether ongoing concerns about vaccine safety are to blame for the measles epidemic.
When should children be vaccinated?
Children should receive the MMR (Mumps, Measles, Rubella) vaccine when they are between 12 and 15 months of age, and then again (a booster) before entering school when they are 4-6 years old. Babies carry their mother's immunity for a few
months after birth if their mothers are immune.
Sometimes babies require vaccination before they are 12
months old. This may happen if there is a serious outbreak in
their area, or if they are going to travel to an area with a serious outbreak. In such cases they can receive the vaccination from the age of 6 months, and will need a booster when they are 12 months old.
Adults do not require a vaccine in the USA if:
They were born before 1957 in the USA, or lived there before 1957.
Received two MMR shots after they were 12 months old.
Had one MMR vaccine plus a second dose of measles vaccine.
Are found to be immune to measles, mumps and rubella
after a blood test
The vaccine should not be taken by:
Pregnant women.
Women who plan to become pregnant very soon (check
with your doctor).
People who are seriously allergic to gelatin or neomycin
(antibiotic).
Anybody who has a condition or disease that affects their
immune system, as well as people receiving treatment which weakens their immune system should ask their doctor whether
they should receive the vaccine.
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