Measles (Rubeola)

Measles is a highly contagious viral disease that can be fatal. 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.
What causes measles?
Measles is caused by the measles virus (a paramyxovirus).
How is measles spread?
The measles virus is highly contagious. 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.
Is measles deadly?
While measles can be fatal, it 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 incubation period for measles?
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?
A typical case of measles actually starts with a
* fever,
* runny nose,
* hacking cough,
* 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?
Some cases of measles have an associated complication. These complications can include diarrhea, ear infections, pneumonia, blindness, acute brain inflammation (encephalitis; very rare), and persistent brain inflammation (subacute sclerosing panencephalitis; extremely rare).
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.
Acute encephalitis, although rare, is extremely dangerous and results in death in a significant percentage 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.
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.
What is the prognosis for measles?
Most people who contract measles will recover completely. Very few 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.
Is it possible to prevent measles with a vaccine?
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 the MMR or MMRV?
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.
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.
What adverse reactions can occur with the measles vaccination?
Adverse reactions to measles vaccination (as part of the MMR) include fever, rash, joint aches, and low platelet count (thrombocytopenia). Some adult women 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.
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.
Who should be revaccinated against measles?
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.