Measles
Measles
What is measles?
Measles is a highly contagious infection of the respiratory system.
What is the infectious agent that causes measles?
Measles is caused by the measles virus.
Where is measles found?
The measles virus is found worldwide. The virus multiplies in cells of the respiratory tract in infected persons and is released into fluids of the nose, throat, and mouth.
How do people get measles?
People get measles when they breathe in tiny droplets that contain the measles virus. The virus attaches to the lining of the airways, multiplies, and causes disease. People can also be infected by direct contact with fluid from the nose or mouth of an infected person.
Measles is very contagious. An uninfected person can get measles simply by breathing the air in a room where an infected person has been. The virus can live in the air for 2 hours after an infected person leaves a room. Infected persons are usually infectious to others even before symptoms appear.
What are the signs and symptoms of measles?
Measles symptoms usually show up in two stages.
The first stage begins with a runny nose, cough, and a slight fever. As the infection progresses, the person's eyes become red and sensitive to light, and the fever rises.
The second stage begins after 3 to 7 days. The fever reaches 103oF-105oF, and a red blotchy rash appears. The rash usually starts on the face and then spreads to the chest, back, and arms and legs, including the palms and soles of the feet. The rash lasts for 4 to 7 days. Small white spots might also appear on the gums and inside of the cheeks.
How is measles diagnosed?
Measles can usually be diagnosed by symptoms. A blood test can confirm the diagnosis.
Who is at risk for measles?
Persons who have not been immunized against measles are the main risk group. Infants are generally protected from measles for 6 to 8 months after birth, due to immunity that was passed on from their mothers. Older children usually receive measles immunization according to state and school health regulations.
Currently, outbreaks of measles are occurring most often on college campuses, among young persons who have not been adequately immunized against measles or whose immunity has decreased since childhood.
What complications can result from measles?
Pneumonia occurs in up to 6 percent of reported measles cases and accounts for 60 percent of deaths from measles. Encephalitis (inflammation of the brain) can also occur. Other complications include middle ear infections and convulsions (seizures).
The risk of complications varies with age. Infants under age 2 years and adults over age 20 have a 20% to 30% chance of complications, often requiring hospitalization. School-age children have a 3% to 5% chance of serious complications.
What is the treatment for measles?
There is no specific treatment for measles. If measles is suspected, a health-care provider should be contacted. The health-care provider can confirm the diagnosis and provide home-care instructions to relieve the discomfort of the symptoms.
How common is measles?
Measles is very common in developing countries. An estimated 43 million cases occur yearly, with more than 1 million deaths. In the United States, about 350 cases are reported each year. Most, if not all, of these cases are in people who became infected in other countries.
Is measles an emerging infectious disease?
Measles continues to be a problem in developing countries. However, U.S. measles cases have been decreasing since 1993. The decrease can be attributed to: 1) increased immunization coverage, 2) the use of a two-dose vaccine strategy for children, and 3) programs to eliminate measles in Mexico and Central and South America.
How can measles be prevented?
Measles can be prevented by immunization. About 95 percent of vaccinated persons are protected with one dose, and practically everyone is protected with two doses.
As is the case with all immunizations, there are important exceptions and special circumstances. Health-care providers should have the most current information on recommendations about the measles immunization.
Where can I find more information about measles?
CDC websites:
NCID (http://www.cdc.gov/ncidod/ncid.htm)
This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above or think that you might have measles, consult a health-care provider.