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Measles is an infectious illness caused by the rubeola virus. It spreads either through direct contact with a person who has the virus or through droplets in the air.
Measles is a highly contagious disease that can lead to life-threatening complications. According to the Centers for Disease Control and Prevention (CDC), around 20% of people in the United States who get measles need to spend time in the hospital, and it is fatal in 1–3 of every 1,000 cases.
Vaccination offers effective protection from measles. Some people cannot have the vaccination due to other health conditions, such as a weakened immune system. However, according to an article published by the World Health Organization (WHO), if 93–95% of the population receives the vaccine, those who are at risk are unlikely to catch measles.
The WHO also estimate that over 140,000 people died from measles in 2018, and most were under 5 years of age. Due to effective vaccination programs, however, this figure 73% lower than it was in 2000.
Measles is a viral disease that causes uncomfortable symptoms and can lead to life-threatening or life-changing complications.
- a fever, possibly up to 104°F (40°C)
- a cough
- a runny nose
- watery eyes
- body aches
- small white spots in the mouth, appearing 2–3 days after early symptoms
- a red rash, appearing around 3–5 days after symptoms start
The rash usually starts at the hairline and spreads down through the body. It may begin as flat, red spots, but small bumps may appear on top. The spots may join together as they spread.
Complications can arise, some of which can be severe.
- vision loss
- encephalitis, an infection that causes brain swelling
- severe diarrhea and dehydration
- additional infections
- pneumonia and other respiratory infections
During pregnancy, measles can lead to:
- loss of pregnancy
- early delivery
- low birth weight
Those most at risk of complications include:
- people with a weakened immune system
- very young children
- adults over the age of 20 years
- pregnant women
Infection with the rubeola virus causes measles.
How symptoms develop
These cells move to the lymph nodes, where the virus transfers to other cells. These cells travel through the body, releasing virus particles into the blood.
As the blood travels around the body, it carries the virus to different body organs, including the liver, the skin, the central nervous system, and the spleen.
In the skin, the measles virus causes inflammation in the capillaries. This gives rise to the hallmark measles rash.
The virus crosses the blood-brain barrier and enters the brain in around 1 in 1,000 people. This can cause swelling in the brain that may be life-threatening.
An infection in the lungs causes a person to cough, which transmits the virus to other people.
Anyone who has never had measles or the vaccination can become ill if they breathe in infected droplets or are in close physical contact with someone who has measles.
The disease is contagious. The CDC indicate that a person can transmit the virus from 4 days before and about 4 days after the rash appears.
The infection spreads through:
- physical contact with a person who has measles
- being near a person with measles when they cough or sneeze
- touching a surface with the virus on and then putting fingers into the mouth, or rubbing the nose or eyes
After a person coughs or sneezes, the virus remains active in the air for around 2 hours.
If one person has measles, they can pass it to up to 90% of those around them, unless they have immunity or have had the vaccination.
Measles only affects humans. No animal species can transmit it.
A person should see a doctor if:
- they have symptoms that could indicate measles
- the fever rises over 100.4º F (38º C)
- there is chest pain or breathing difficulty
- they cough up blood
- there are signs of confusion or drowsiness
- they experience a convulsion
A doctor can usually diagnose measles by looking at the signs and symptoms, but they may order a blood test to confirm a diagnosis.
There is no specific treatment for measles, and symptoms usually go away within 7 to 10 days.
If there are no complications, the doctor will recommend rest and plenty of fluids to prevent dehydration. If there is a risk of complications, the doctor may recommend spending time in the hospital.
If a child needs treatment in the hospital, a doctor will prescribe vitamin A.
The following tips may help manage symptoms:
- Pain and fever: Tylenol or ibuprofen can help manage a fever, aches, and pains. A doctor can advise on options for young children. Children under 16 years should not take aspirin.
- A cough: Use a humidifier or put a wet towel on a warm radiator to moisten the air. A warm lemon and honey drink may help, but do not give honey to babies under 1 year.
- Dehydration: Encourage the person to drink plenty of fluids.
- Eyes: Remove any crustiness with cotton wool soaked in water. Dim the lights if the eyes are hypersensitive.
The measles is a viral infection, and antibiotics will not help. However, a doctor may prescribe them if a person develops an additional bacterial infection.
After a person has measles once, they usually have immunity and are unlikely to have it again.
A doctor will usually recommend vaccination for those who have not had measles and do not have immunity.
In the United States, the CDC recommend that people have the measles, mumps, and rubella (MMR) vaccine as follows:
- one shot at 12–15 months of age
- a booster shot at 4–6 years, before starting school
Newborns have immunity from their mother for several months after birth if the mother has immunity.
In some cases, however, a doctor may recommend vaccination before the age of 12 months. This may happen if there is a risk of an outbreak in the area where they live.
Adults do not need a vaccine in the U.S. if:
- They were born or lived in the U.S. before 1957 unless they work in a healthcare setting and have no evidence of immunity.
- They received at least one MMR shot after the age of 12 months, or two doses for those at high risk, such as healthcare workers.
- A blood test shows they have immunity.
Some people should not have the vaccine. They include those who:
- are pregnant or may be pregnant
- have certain allergies
- have a personal or family history of immune system problems
- have tuberculosis
- currently feel moderately to severely unwell
- have had another vaccination within the last 4 weeks
Anybody who is not sure whether they should have the vaccine should ask their doctor for advice.
When considering whether or not to opt for vaccination, it is essential to talk to a doctor about how the risks of measles compare with the risks of a vaccine.