Measles

What is measles?

Measles is a highly contagious viral disease that can kill you. Although an uncommon disease in the United States of America, in 2008, measles killed 164,000 children worldwide. In most people, the disease produces fever (temperature > 101 F [38.3 C]), a generalized rash that last greater than three days, cough, runny nose (coryza), and red eyes (conjunctivitis). The complications of measles that result in most deaths include pneumonia and inflammation of the brain (encephalitis).

What is rubeola?

Rubeola is the scientific name used for measles. It should not be confused with rubella (German measles).

What is rubella?

Rubella is the scientific name used of German measles, a different viral illness. While German measles is rarely fatal, it is dangerous in that it causes birth defects and can cause miscarriage and fetal death.

What are other names for measles?

Other terms have been used to describe measles. These include (erroneously) rubella, hard measles, red measles, seven-day measles, eight-day measles, nine-day measles, 10-day measles, and morbilli.

What is the history of measles?

Cases of measles were described as early as the seventh century. However, it was not until 1963 that researchers first developed a vaccine to prevent measles. Before the vaccine was made available, almost every child became infected with the virus because it is so easily spread. Before routine vaccination, there were approximately 3-4 million cases of measles and 500 deaths due to measles each year in the United States.

There were initially two types of vaccines developed against measles. One was developed from a virus that had been killed, and the other was developed using a live measles virus that was weakened (attenuated) and could no longer cause the disease. Unfortunately, the killed measles virus (KMV) vaccine was not effective in preventing people from getting the disease, and its use was discontinued in 1967. The live virus vaccine has been modified a number of times to make it safer (further attenuated) and today is extremely effective in preventing the disease. The currently used vaccine is a live attenuated vaccine.

What causes measles?

Measles is caused by the measles virus (a paramyxovirus).

How is measles spread?

Measles is spread through droplet transmission from the nose, throat, and mouth of someone who is infected with the virus. These droplets are sprayed out when the infected person coughs or sneezes. Among unimmunized people exposed to the virus, over 90% will contract the disease. The infected person is highly contagious for four days before the rash appears until four days after the rash appears. The measles virus can remain in the air (and still be able to cause disease) for up to two hours after an infected person has left a room.

How does one become immune to measles?

Anyone who has had measles is believed to be immune for life. People who have received two doses of vaccine after their first birthday have a 98% likelihood of being immune. Infants receive some immunity from their mother. Unfortunately, this immunity is not complete, and infants are at increased risk for infection until they receive the vaccination at 12 to 15 months of age.

Who is at risk for getting measles?

Those people at high risk for measles include:

• children less than 1 year of age (although they have some immunity passed from their mother, it is not 100% effective);

• people who have not received the proper vaccination series;

• people who received immunoglobulin at the time of measles vaccination;

• people immunized from 1963 until 1967 with an older ineffective killed measles vaccine.

Are measles deadly?

Measles can kill you. In 2008, approximately 164,000 people died of measles in the world. However, measles is rarely fatal in the United States. This is due to the fact that most people are immunized, which results in very infrequent outbreaks. Also, people most likely to have complications (including death) are those who are malnourished or who have weakened immune systems

What is the danger of getting measles while pregnant?

If you contract measles while you are pregnant, you may have a miscarriage, a stillbirth, or a preterm delivery. There appears to be no risk of having birth defects (unlike an infection with the rubella virus, known as German measles).

If I am exposed, how long does it take to develop symptoms?

The typical time from exposure to a person infected with measles to development of the initial symptoms is 10-12 days (the range is seven to 21 days). The rash occurs a few days after the initial symptoms (ranges from seven to 18 days from exposure).

What are measles symptoms and signs?

The typical case of measles actually starts with a fever, runny nose, hacking cough, and red eyes. After two to four days of these symptoms, the patient may develop spots within the mouth called Koplik's spots. These spots look like little grains of white sand surrounded by a red ring and are usually found inside the cheek toward the back of the mouth (opposite the first and second upper molars).
The skin rash (also known as an exanthem or exanthema) appears three to five days after the onset of the initial symptoms (fever, cough, runny nose, and red eyes). The rash is a flat to slightly raised (maculopapular) red rash that usually last five to six days. It begins at the hairline and then progresses to the face and upper neck. Over the next two to three days, the rash progresses downward to cover the entire body, including the hands and feet. The rash has mostly distinct lesions, but some may overlap (become confluent). Initially, these lesions will turn white when you press on them (blanch). After three to four days, they no longer will blanch. As the rash begins to fade, there will often be a fine flaking of the skin (desquamation). The rash fades in the same order that it appears.
The fever that occurs with measles is called a stepwise fever. The patient starts with a mild fever that progressively gets higher. Fevers often reach temperatures greater than 103 F (39.4 C).
Although not as common as other symptoms, some patients may have a sore throat.

What complications are seen with measles?

Approximately 30% of cases of measles have an associated complication. These complications can include diarrhea (8%), ear infections (7%), pneumonia (6%), blindness (1%), acute brain inflammation (encephalitis) (0.1%), and persistent brain inflammation (subacute sclerosing panencephalitis) (0.0001%).
Blindness associated with measles is due to a combination of poor nutrition (specifically vitamin A deficiency) and the measles infection. Prevention is the most effective treatment. In third-world countries, post-measles blindness is the leading cause of blindness, with up to 60,000 cases occurring annually.
Acute encephalitis, although rare, is extremely dangerous and results in death in approximately 15% of patients who develop it. When it occurs, acute encephalitis generally starts six days after onset of the rash. Symptoms can include fever, headache, vomiting, stiff neck, drowsiness, seizures, and coma.
Subacute sclerosing panencephalitis (SSP) is an extremely rare degenerative condition of the brain and spinal cord (central nervous system). It is believed to be caused by a chronic infection of the central nervous system with the measles virus. Typically, symptoms start years after the patient had measles (average seven years, range one month to 27 years). The patient has a slow and progressive loss of brain function, seizures, and eventually death results. There is no known treatment for SSP.
Most deaths from measles are due to pneumonia in children and encephalitis in adults. There are approximately 2.2 deaths per 1,000 people who get the measles. The people most likely to have complications (including death) are those who are malnourished or who have weakened immune systems (for example, people with AIDS or other conditions that weaken the immune system).

What is atypical measles?

Atypical measles occurs in people who received the killed measles vaccine (KMV; only used from 1963 until 1967) and who are exposed to wild-type measles virus. The KMV unfortunately sensitizes the patient to the measles virus but does not offer any protection. The disease is characterized by fever, pleural effusions, pneumonia, and swelling of the extremities. The rash of atypical measles is different from measles in that it may have an urticarial component (hives) and usually appears first on the ankles and wrists.
It is recommended by the U.S. Centers for Disease Control and Prevention (CDC) that people who may have received the KMV should receive revaccination with the live measles vaccine.
The virus can be isolated in tissue culture in the lab. Blood (serologic) tests are also available.

What is modified measles?

Modified measles is seen in patients who, because they were unimmunized, received immune globulin after being exposed to a patient with measles. It is also seen occasionally in young infants who have limited immunity from their mothers. The immune globulin prolongs the time from exposure to onset of symptoms (incubation period). When the symptoms do occur, they are much milder than those seen with normal measles and tend to last a shorter period of time.

How is the diagnosis of measles made?

The diagnosis of suspected measles is mostly clinical, meaning that the appearance and history of the patient suggest the diagnosis. In a person with known exposure to someone with measles or travel to a foreign country, measles should always be considered when faced with a patient who has high fever and characteristic rash. Until the rash appears, the presence of Koplik's spots should help to suggest the diagnosis. Most cases of suspected measles in the United States turn out not to be measles (see below). It is recommended that the diagnosis be confirmed using a blood test for IgM, a type of antibody against the virus. If the IgM test is positive, viral cultures should be obtained. The state and local health department should be contacted immediately for any suspected case in order to follow the correct procedures for viral culture and isolation of the patient. Further information on laboratory testing of suspected cases is available from the CDC (http://www.cdc.gov/vaccines/pubs/surv-manual/chpt07-measles.htm).

If it is not measles, what else could it be?

There are a large number of infectious diseases and other conditions that can cause some of the symptoms of measles. These include, but are not limited to, dengue fever, drug rashes, enteroviral infections, fifth disease, German measles (rubella), Kawasaki disease, Rocky Mountain spotted fever, roseola, and toxic shock syndrome. It is important that suspected cases be seen by a medical expert and appropriate laboratory tests be ordered.

What should I do if I have been exposed to measles?

People who have been appropriately vaccinated (or who have had the disease) and who are exposed to a patient with measles do not need to do anything. If an unimmunized person is exposed to a patient with measles, they should receive the vaccine as soon as possible. This may prevent the disease if given within 72 hours of exposure. Immune globulin may have some benefit if given within six days of exposure. The CDC recommends that immune globulin be utilized for household contacts of infected people, immunocompromised people, and pregnant women. It is not recommended that immune globulin be utilized to control a measles outbreak.

Is there any treatment for measles after symptoms and signs develop?

The treatment of patients with measles is mostly focused upon symptom relief. Specific complications like pneumonia may require antibiotics. Patients should be on bed rest until the fever has resolved and should remain well hydrated. In malnourished patients, vitamin A supplementation is recommended. Patients should be isolated to prevent spread of the disease.

If measles only rarely occurs in the United States, why should I get vaccinated?

Although measles only rarely occurs in the United States, it still does occur and can be fatal. In the year 2000, almost 1 million children died of the disease. Through a very intensive effort by the World Health Organization, this was decreased to only 164,000 in 2008. When the number of vaccinated individuals starts to decrease, we see the disease start to occur more frequently. This occurred from 1989 until 1991 in the U.S. During that period, there were 55,000 cases and 123 deaths from measles in the U.S. Due to a massive public-health effort, almost all children in the U.S. now receive measles vaccine before they are allowed to enter school. The number of cases of measles in the U.S. dropped to only 37 in 2004. Most cases are now from outside the U.S. (commonly from adopted children from China), although some cases occur as people in this country are exposed to the infected international traveler.

What is the prognosis for measles?

Most people who contract measles will recover completely. Only 2.2 out of 1,000 people who get measles will die. People who are malnourished or immunocompromised are more likely to have complications or die. However, it is possible for any person to die from the measles, which highlights the importance of becoming vaccinated. Almost no one who has been vaccinated has died from the disease.

How can I prevent contracting measles?

The only way to prevent measles is by receiving measles immunization: This is commonly given as a shot containing measles, mumps, and rubella vaccine (MMR) or a shot containing measles, mumps, rubella, and varicella vaccine (MMRV). The MMRV is not recommended for anyone older than 12 years of age. The current recommendation is that everyone receives two doses of the vaccine after 1 year of age. If the vaccine is received before 1 year of age, the person should receive two additional doses.
The measles vaccine is also available as a single vaccine; however, in most cases, there is no reason to utilize the measles vaccine alone without mumps and rubella vaccine. The complete schedule of recommended vaccinations is available from the CDC (http://www.cdc.gov/vaccines/recs/schedules/child-schedule.htm).

Is there any truth to the fear of getting autism from vaccines?

There is no valid scientific evidence that the measles vaccine, or any other vaccine, is the cause of autism. The possibility of an association between the measles vaccine and autism was proposed by Andrew Wakefield and colleagues in 1998. The research published by Wakefield was found to be flawed and actually forged, and the results have not been able to be repeated by other researchers. Since 1998, there have been numerous studies that have examined for such an association. None of these studies have shown any risk of autism associated with the use of the vaccine. A recent study performed in Japan after the MMR vaccine was removed from the market showed that autism continued to increase after the vaccine was no longer being utilized. Although autism is a very serious disease that warrants good research to find out its many causes, not obtaining vaccinations is potentially dangerous and not supported by the best scientific data available today.

Who should not receive measles vaccinations?

The following groups of people should not receive measles vaccinations:

• People who have suffered a severe allergic reaction to either the measles vaccine or its components (gelatin or neomycin) should not receive the vaccine.

• Women known to be pregnant should not receive the vaccine. Pregnancy should be avoided for four weeks after vaccination.

• Severely immunocompromised patients (cancer patients or patients who are receiving large doses of corticosteroids) should not receive the vaccine. However, those leukemia patients who have been in remission for three months may receive the MMR.

• Patients with severe human immunodeficiency virus (HIV) infections should not receive the vaccine. However, asymptomatic patients with HIV are considered to be safe for vaccination. The CDC has issued guidelines for vaccination based on the CD4+ T-lymphocyte counts.

• People with a moderate to severe acute illness should wait until their illness resolves before receiving the vaccine.

Patients with history of thrombocytopenic purpura or thrombocytopenia (low platelets) may be at increased risk, and immunization should be decided on a case-by-case basis.

If a child has an egg allergy, can they still receive the measles vaccine?

Although the measles vaccine is made using chick embryos, there is no evidence of increased reactions in people with an egg allergy. Therefore the CDC recommends giving MMR vaccine to egg-allergic children without any prior skin testing or the use of special protocols.

What adverse reactions can occur with the measles vaccination?

Adverse reactions to measles vaccination (as part of the MMR) include fever (5%-15%), rash (5%), joint aches (5%), and low platelet count (thrombocytopenia; one instance per 30,000 doses). In adult women, up to 25% will suffer joint pain that is due to the rubella component of the vaccine. The fever usually occurs seven to 12 days after the vaccination, and the rash occurs seven to 10 days after vaccination.

Who should be revaccinated?

The following group of people should be considered unvaccinated and should receive at least one dose of vaccine:

• People vaccinated before their first birthday should be revaccinated.

• Anyone known to have been vaccinated with the killed measles vaccine (KMV) should be revaccinated.

• Anyone vaccinated with KMV who received their dose of live measles vaccine with four months of their last dose of vaccine should be revaccinated.

• Anyone vaccinated before 1968 in whom it is not known if the vaccine was KMV or not should be revaccinated.

Where can I find more information about measles?

1. http://wwwn.cdc.gov/travel/yellowBookCh4-Measles.aspx

2. http://www.cdc.gov/vaccines/pubs/
pinkbook/downloads/meas.pdf

3. http://www.cdc.gov/vaccines/pubs/surv-manual/chpt07-measles.htm

4. http://www.who.int/mediacentre/factsheets/fs286/en/

5. http://www.who.int/vaccines-documents/GlobalSummary/GlobalSummary.pdf

6. http://www.immunize.org/catg.d/p2065.pdf (autism)

Measles At A Glance

• Measles is a potentially serious disease.
• Measles is due to a virus that is easily spread.
• Measles can be complicated by ear infections, pneumonia, or encephalitis.
• Measles infection of the brain (encephalitis) can cause convulsions, mental retardation, and even death.
• Measles in pregnant women can cause miscarriages or premature delivery.
• Measles can be prevented through vaccination.
• Each person not immunized against measles is at risk for measles and puts others at risk.

REFERENCES:

American Academy of Pediatrics. "Measles." Red Book: 2006 Report of the Committee on Infectious Diseases, 28th ed. Ed. Pickering, L.K. Elk Grove Village, IL: American Academy of Pediatrics, 2006.

Perry, R.T., and N.A. Halsey. "The Clinical Significance of Measles: A review." J Infect Dis 189 (2004): S4–16.

United States. Centers for Disease Control and Prevention. "Measles." Manual for the Surveillance of Vaccine-Preventable Diseases, 4th ed. 2008. <http://www.cdc.gov/vaccines/pubs/surv-manual/chpt07-measles.htm>.

United States. Centers for Disease Control and Prevention. "Measles, Mumps, and Rubella -- Vaccine Use and Strategies for Elimination of Measles, Rubella, and Congenital Rubella Syndrome and Control of Mumps: Recommendations of the Advisory Committee on Immunization Practices (ACIP)." MMWR 47 (No. RR-8) 1998: 1–57.

United States. Centers for Disease Control and Prevention. "Notes from the Field: Measles Transmission Associated With International Air Travel -- Massachusetts and New York, July -- August 2010." MMWR 59.33 Aug. 2010: 1073.

United States. Centers for Disease Control and Prevention. "Use of Combination Measles, Mumps, Rubella, and Varicella Vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP)." MMWR 59(RR03) 2010: 1-12.

World Health Organization. "Fifty-Sixth World Health Assembly. Agenda item 14.7. Reducing Global Measles Mortality." Geneva: World Health Organization, 2003. <http://www.who.int/gb/ebwha/pdf_files/WHA56/ea56r20.pdf>.