Measles
(Rubeola · Morbilli · Red Measles)
In this condition factsheet:
The Facts on Measles
Measles (also called rubeola or morbilli) was once one of the most common childhood infections in North America. In the early 1960s, over half a million children were infected every year. In 1963, the creation of a measles vaccine changed everything. Today, while very few new cases of measles occur each year in developed countries, it still occurs in epidemic proportions in developing regions, infecting around 10 million people and causing around 100,000 to 200,000 deaths worldwide.
Even though a majority of patients recover from infection, measles can have serious complications. Early in infection, the brain tissue can become inflamed (encephalitis). A later complication can occur several years later, causing brain damage.
Measles is one of the most contagious vaccine-preventable infections in humans. The one antigenic type of the measles virus is only found in humans. This means that if high immunization rates are maintained, it may be possible to eradicate this virus, just like smallpox and polio.
Causes of Measles
Measles is caused by a type of virus called a paramyxovirus. It is a highly contagious virus, usually transmitted in tiny droplets when an infected person coughs, breathes, or sneezes. The measles virus can also survive for approximately 2 hours on infected surfaces like doorknobs and telephones. Research shows that only 10% of unvaccinated people who share a house with a measles patient avoid infection.
Symptoms and Complications of Measles
For 1 or 2 weeks after an infection, the virus multiplies without causing any symptoms. This is called the incubation period. After that, symptoms such as cough, fever, runny nose, red eyes, and tearing will appear. Children may also become irritable.
About 2 days after initial symptoms appear, small, red, irregular spots with a whitish or bluish centre called Koplik's spots develop on the inside of the cheeks near the molars. About 2 days after Koplik's spots develop, a rash (large brown or red blotches) develops behind the ears, and perhaps on the forehead and face, and can spread to the trunk, arms, and legs. The rash usually begins to fade within 5 days, often starting at the top (head) before it clears up in the lower parts of the body (legs). Once the rash has completely disappeared, the skin may appear a bit brownish and the top skin layers may peel off soon afterwards.
The rash isn't painful and does not itch. Some people may experience increased sensitivity to light, and their eyes may become red and inflamed. During the peak of the infection, a fever usually develops with a body temperature as high as 40°C (104°F).
Measles is contagious for about 4 days before the rash appears and about 5 days afterwards. It's best for people with measles to stay away from others so they won't get infected.
Measles usually runs a simple course with few complications, but in certain cases, problems can arise. The most common complication is pneumonia, an infection of the lungs, especially in people with weakened immune systems. This is the most common cause of death from measles in young children. A second common infection that occurs as a result of the measles virus is a middle ear infection (otitis media). These infections can possibly cause permanent hearing loss.
In about 1 in 1,000 cases, measles can affect the brain, causing encephalitis. This usually happens during the late stages of infection, 2 to 14 days after the rash develops. Unfortunately, there's no cure, but some people may recover on their own without any further problems. Many people, however, are left with permanent problems such as seizures.
In a small number of patients, the virus can take permanent rest in the brain and be awakened years later to cause re-infection and brain damage. This results in a condition called subacute sclerosing panencephalitis (SSPE), which is often fatal. This condition is very rare, occurring about 7 to 10 years after measles virus infection.
Measles can also cause complications such as hepatitis (inflammation of the liver) or appendicitis (inflammation of the appendix). Very rare complications include heart and kidney problems.
Pregnant women who catch measles have a greater risk of miscarriage.
