The National Academies: What You Need To Know About Infectious Disease

The National Academies

What You Need To Know About Infectious Disease


Measles is a highly contagious respiratory disease caused by a virus. The virus lives in mucus in the nose and throat of an infected person. The disease can spread through the air by breathing, coughing, or sneezing. Measles is very rare in countries and regions of the world that are able to keep vaccination coverage high. In North and South America, Finland, and some other areas, endemic measles transmission is considered to have been stopped through vaccination. However, worldwide there are estimated to be 20 million cases and 197,000 deaths each year. More than half of the deaths occur in India.

A typical case of measles begins with mild to moderate fever, cough, runny nose, red eyes, and sore throat. Two or 3 days after symptoms begin, tiny white spots may appear inside the mouth. Three to 5 days after the start of symptoms, a red or reddish-brown rash appears. The rash usually begins on a person’s face at the hairline and spreads downward to the neck, trunk, arms, legs, and feet. When the rash appears, a person’s fever may spike to more than 104°F. After a few days, the fever subsides and the rash fades.

There is no specific treatment for measles. However, acetaminophen, general bed rest, and humidified air can all help relieve symptoms. In some developing countries, where children do not get enough vitamin A, supplements may also reduce the risk of death and complications. It is not clear whether children in more developed countries would benefit from supplements.

Measles can be prevented by the combination MMR (measles, mumps, and rubella) vaccine. In the decade before the measles vaccination program began, an estimated 3 to 4 million people in the United States were infected each year, of whom 400 to 500 died and 48,000 were hospitalized. Another 1,000 developed chronic disability from measles encephalitis. Widespread use of measles vaccine has led to a greater than 99 percent reduction in measles cases in the United States compared with the pre-vaccine era. In 2009, only 71 cases of measles were reported in the United States.


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What do you know about infectious disease?

True or False: Our bodies contain at least 10 times more human cells than bacterial cells.

  • Sorry, that’s incorrect.

    Our bodies contain at least 10 times more bacterial cells than human cells. 

  • Correct!

    Our bodies contain at least 10 times more bacterial cells than human cells. 

Infectious Disease Defined

El NiƱo-Southern Oscillation Cycle (ENSO)
An irregular event that disrupts regional and global weather patterns when unusually warm surface water flows across the Pacific Ocean toward and along the coast of South America, preventing the upwelling of nutrient-rich, cold deepwater.

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