Overview of Measles Disease
Measles is a respiratory disease caused by a virus. The disease of measles and the virus that causes it share the same name. The disease is also called rubeola. Measles virus normally grows in the cells that line the back of the throat and lungs.
Measles causes fever, runny nose, cough and a rash all over the body. Visit the Signs and Symptoms page for more information, and the Photos of Measles page to see pictures of people with the measles rash.
About one out of 10 children with measles also gets an ear infection, and up to one out of 20 gets pneumonia. About one out of 1,000 gets encephalitis, and one or two out of 1,000 die. Other rash-causing diseases often confused with measles include roseola (roseola infantum) and rubella (German measles).
While measles is almost gone from the United States, it still kills nearly 200,000 people each year around the world. Measles can also make a pregnant woman have a miscarriage or give birth prematurely. For more information, visit the Complications page.
Measles spreads through the air by breathing, coughing or sneezing. It is so contagious that any child who is exposed to it and is not immune will probably get the disease. See the Transmission page for more information.
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 interrupted through vaccination. There are still sporadic cases of measles in the United States because visitors from other countries or US citizens traveling abroad can become infected before or during travel and spread the infection to unvaccinated or unprotected persons.
Worldwide, there are estimated to be 10 million cases and 197,000 deaths each year. More than half of the deaths occur in India. For more information on measles in the United States and worldwide, visit the Global Elimination page.
One of the earliest written descriptions of measles as a disease was provided by an Arab physician in the 9th century who described differences between measles and smallpox in his medical notes.
A Scottish physician, Francis Home, demonstrated in 1757 that measles was caused by an infectious agent present in the blood of patients. In 1954 the virus that causes measles was isolated in Boston, Massachusetts, by John F. Enders and Thomas C. Peebles. Before measles vaccine, nearly all children got measles by the time they were 15 years of age. Each year in the United States about 450 people died because of measles, 48,000 were hospitalized, 7,000 had seizures, and about 1,000 suffered permanent brain damage or deafness. Today there are only about 50 cases a year reported in the United States, and most of these originate outside the country.
Signs and Symptoms of Measles
The symptoms of measles generally begin about 7-14 days after a person is infected, and include:
- Blotchy rash
- Runny nose
- Red, watery eyes (conjunctivitis)
- Feeling run down, achy (malaise)
Tiny white spots with bluish-white centers found inside the mouth (Koplik’s spots). A typical case of measles begins with mild to moderate fever, cough, runny nose, red eyes, and sore throat. Two or three days after symptoms begin, tiny white spots (Koplik’s spots) may appear inside the mouth.
Three to five 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 degrees Fahrenheit.
After a few days, the fever subsides and the rash fades.
Transmission of Measles
Measles is highly contagious and can be spread to others from four days before to four days after the rash appears. Measles is so contagious that if one person has it, 90% of the people close to that person who are not immune will also become infected with the measles virus.
The virus lives in the mucus in the nose and throat of the infected person. When that person sneezes or coughs, droplets spray into the air. The droplets can get into other people’s noses or throats when they breathe or put their fingers in their mouth or nose after touching an infected surface. The virus can live on infected surfaces for up to 2 hours and spreads so easily that people who are not immune will probably get it when they come close to someone who is infected.
Measles is a disease of humans; measles virus is not spread by any other animal species.
Complications of Measles
About 30% of measles cases develop one or more complications, including
- Pneumonia, which is the complication that is most often the cause of death in young children.
- Ear infections occur in about 1 in 10 measles cases and permanent loss of hearing can result.
- Diarrhea is reported in about 8% of cases.
These complications are more common among children under 5 years of age and adults over 20 years old.
Even in previously healthy children, measles can be a serious illness requiring hospitalization. As many as 1 out of every 20 children with measles gets pneumonia, and about 1 child in every 1,000 who get measles will develop encephalitis. (This is an inflammation of the brain that can lead to convulsions, and can leave the child deaf or mentally retarded.) For every 1,000 children who get measles, 1 or 2 will die from it. Measles also can make a pregnant woman have a miscarriage, give birth prematurely, or have a low-birth-weight baby.
In developing countries, where malnutrition and vitamin A deficiency are common, measles has been known to kill as many as one out of four people. It is the leading cause of blindness among African children. Measles kills almost 1 million children in the world each year.
See also: The Measles chapter of the Epidemiology and Prevention of Vaccine Preventable Diseases (Pink Book) that describes measles complications in more depth. 
Measles can be prevented by the combination MMR (measles, mumps, and rubella) vaccine. In the decade before the measles vaccination program began, an estimated 3–4 million people in the United States were infected each year, of whom 400–500 died, 48,000 were hospitalized, and another 1,000 developed chronic disability from measles encephalitis. Widespread use of measles vaccine has led to a greater than 99% reduction in measles cases in the United States compared with the pre-vaccine era.
However, measles is still common in other countries. The virus is highly contagious and can spread rapidly in areas where vaccination is not widespread. It is estimated that in 2007 there were 197,000 measles deaths worldwide—that equals about 540 deaths every day or about 22 deaths every hour.
For Those Getting Vaccinated
Vaccination recommendations and other useful information about the measles vaccine
- Measles Vaccine Basics. 
- Beliefs & Concerns. 
- Vaccine Safety. 
- Who Should Not be Vaccinated?. 
Clinical Information for Healthcare Professionals
Measles references and resources, provider education tools, and materials for patients
- Clinical Information on Measles. 
- Vaccine Recommendations. 
- References & Resources. 
- Provider Education. 
- Materials for Patients. 
Estimates of the number of people living in the U.S. who have been received particular vaccines at the national, state, and local levels using results from the National Immunization Survey.
- Immunization Coverage in the U.S. 
- School and Childcare Vaccination Surveys. 
During 2008, more measles cases were reported than in any other year since 1997. More than 90% of those infected had not been vaccinated, or their vaccination status was unknown. These cases remind us that it is very important to vaccinate children and adults to protect them against measles. Even though the ongoing transmission of endemic (native) measles was declared eliminated in the U.S. in 2000, the disease is still common in many other countries and can be imported into the U.S. by foreign visitors or returning travelers who are not fully protected against the disease. Close to 90% of the measles cases reported in the U.S. during 2008 were either acquired abroad or linked to imported cases.
See also: The Surveillance Manual chapter on measles that describes case investigation, outbreak investigation, and outbreak control for additional information. 
Measles remains a common disease in many countries throughout the world, including some developed countries in Europe and Asia. Approximately half of all imported measles cases occur in U.S. residents returning from visits to foreign countries. The links below provide valuable information to help travelers protect themselves and others from measles.
- Travelers Health: Yellow Book. 
- Measles - Recommendations for Prevention for Travelers. 
- Travelers Health: In the News - 2009 Measles Update. 
Measles Statistics and Surveillance
The highly contagious measles virus is often brought into the United States by travelers or people from other countries. Each imported measles case could start an outbreak, especially if undervaccinated groups are exposed. Surveillance and prompt investigation of cases and contacts help to stop the spread of disease. The links below provide information about measles surveillance and statistics.
National Immunization Survey. 
Surveillance Manual – Chapter 7: Measles. 
Measles Surveillance Worksheet and Instructions. 
National Notifiable Diseases Surveillance System. 
Measles Fast Stats. 
Notifiable Diseases/Deaths in Selected Cities Weekly Information. 
WHO Statistics on Measles. 
Measles Media Materials
- Most U. S. Measles Cases Reported since 1996. 
- CDC Urges Travelers to Israel to Protect Themselves from Measles. 
- CDC Recommends Temporary Suspension of Adoptions from Chinese Orphanage in Response to Measles Outbreak. 
Press Briefing Transcripts
- Update on Measles Outbreaks Throughout the United States. 
- CDC Update on Measles Outbreaks in United States. 
- West Nile Virus activity in the United States, Measles Outbreak in the Marshall Islands and Preparing for Hurricane Isabel. 
Measles Textbooks and Publications
Textbooks and Guidelines
- Epidemiology and Prevention of Vaccine-Preventable Diseases: Measles. 
- Travelers Health: Yellow Book: Measles. 
- Surveillance Manual – Chapter 7: Measles. 
- MMWR Articles. 
- Notifiable Diseases/Deaths in Selected Cities Weekly Information. 
- WHO Measles and Rubella Laboratory Documents. 
- PAHO Measles Featured Items. 
- PAHO Measles Weekly Bulletins. 
- PAHO Immunization Field Guides. 
Global Elimination of Measles
As of November 2002, measles is no longer an endemic disease in the Americas. This demonstrates the effectiveness of current control strategies in a large geographic area. The information below describes the things that CDC and its partners are doing to reach global measles elimination goals.
- Measles Elimination and Control Initiatives. 
- Global Goal to Cut Measles Deaths Surpassed. 
- Global Partners and Related Websites.