Measles

Definition
Measles is a highly contagious viral illness. Early symptoms are followed by a rash. Most people recover from measles without a problem, but mild to potentially life-threatening complications are possible. Measles is also known as rubeola, red measles and the seven- or 10-day measles. Thanks to the introduction of a vaccine in 1963, the prevalence of measles has significantly diminished. Before the vaccine was available, nearly all children developed measles.

Causes/associated factors
Measles is caused by a paramyxovirus, a group of viruses that also cause mumps and certain types of respiratory infections, such as croup. It occurs most often in late winter and spring. Once the respiratory tract is infected, the disease spreads through the rest of the body through the bloodstream. Skin and mucous membranes are affected the most. Once you have measles, you will not get it again.
Before widespread use of the measles vaccine, measles was most common during childhood. Today, it's most prevalent in young children who have not yet been vaccinated and older children and adults who only received one dose of the vaccine. Children born to women who are immune to measles are usually protected by their mother's antibodies for the first six to nine months of life.


Transmission
Measles is spread by inhaling or direct contact with infected respiratory droplets. The incubation period (time from exposure until symptoms appear) averages 10 to 12 days from exposure to the first set of symptoms, but this period can vary from seven to 18 days. The condition is contagious approximately four days before through four days after the rash appears.

Signs/symptoms
Initial symptoms last for two to four days and may include:
profuse runny nose
cough
red, watery eyes that are sensitive to light
fever
appetite loss
Then, you may notice Koplik's spots, which are red spots with white center, in your mouth or throat. These spots usually disappear after 12 to 18 hours.

Final symptoms include a sudden rise in temperature as a red, blotchy rash develops. This rash typically appears on the second to fourth day of illness. It first appears on the forehead around the hairline. Within 24 to 36 hours, it spreads to the face, neck, behind the ears and then to the chest, abdomen, arms, legs and finally the feet. This rash may last four to seven days and will disappear in the same order it appeared. The severity of the illness is proportional to the extent of the rash.

If you or your child develop these symptoms, contact your doctor for a diagnosis.


Diagnosis
Diagnosis is based on symptoms. In some cases, blood tests may be done to test for measles antibodies (compounds that help neutralize or destroy foreign substances in the blood). The virus can also be identified through tissue or fluid samples taken from the nose, throat, blood or urine, but these tests are rarely used in the routine diagnosis of measles.

Treatment
Get plenty of rest, drink lots of liquids and monitor your temperature. You may want to use a cool mist humidifier to soothe your cough. Your doctor may recommend acetaminophen for pain and fever or a medication for the cough. Discuss your treatment and any change in symptoms with your doctor.

Complications
Measles can lead to serious complications, especially in very young or malnourished children and anyone whose immune system is not functioning normally. Complications may include:
ear infections
pneumonia (a lung infection)
croup (an infection that causes the swelling and narrowing of the large air passages, especially the trachea and larynx)
diarrhea
myocarditis (inflammation of the lining of the heart)
For about one in 1,000 cases of measles, encephalitis (inflammation of the brain that often results in permanent brain damage) may develop. Measles is fatal for one to two of every 1,000 reported cases in the United States.


Pregnancy-specific information
Contracting measles during pregnancy increases the chance of miscarriage, premature labor and low birthweight, but does not cause birth defects. If you contract measles near the time of delivery, the baby may catch the infection and develop serious complications.
The measles vaccine is not safe during pregnancy due to possible effects on the fetus. However, you may receive immune globulin (a protein that can act as an antibody, a compound that helps neutralize or destroy foreign substances in the blood) if you're not immune to measles and know you have been exposed to the disease. If it's given within six days of exposure to the virus, the immune globulin may make the illness milder or prevent it completely.


Senior-specific information
The risk of measles for people over age 65 is low because most people in this age group have had the measles, often as children.

Prevention
If you have measles, do everything possible to stay away from others who may not be immune to the measles virus until you've had the rash for five days.
Immunization is the most effective way to prevent measles and its complications. Before the use of the vaccine in the United States, each year there were about 500,000 cases of measles and 50 deaths. In recent years, there have been less than 200 cases per year.

The measles vaccine is a live vaccine made of the weakened measles virus. Children routinely receive the measles vaccine in combination with the mumps and rubella vaccine (known as MMR for measles, mumps and rubella). The first dose is given between ages 12 and 15 months, and a booster shot is given between ages 4 and 6. Children who have not been immunized according to this schedule can begin or complete the series any time. The second dose should be given at least four weeks after the first.

For adults, measles vaccination is recommended if you were born in 1957 or later and haven't had the measles or were never vaccinated. This is especially important for health care workers, international travelers and students. The measles vaccine is also recommended for unvaccinated health care workers of any age who don't have a history of measles or a positive test for measles immunity.

If you received a measles vaccine before 1968, you may have incomplete immunity. One type of vaccine that was given then may leave you susceptible to an atypical measles with mild initial symptoms, including a rash in body creases. A new vaccination is recommended because even atypical measles can have complications such as swollen lymph nodes, an enlarged spleen or liver, and an altered sense of touch. The vaccine given today offers more complete immunity.

The measles vaccine should not be given if you are pregnant or had a severe allergic reaction to gelatin, neomycin or a prior dose of the vaccine. Your doctor may also not recommended if your immune system is not functioning properly (due to cancer, severe HIV infection or long-term treatment with steroid medication, for example).

Immunization may be delayed if you:

have received a blood product containing an antibody (such as platelets, a blood transfusion or an immune globulin) within the last three to 11 months (depending on the product) or will receive such a product in the next two weeks
have had thrombocytopenia (a decrease in the number of platelets, substances that help blood clot)
are currently ill
After exposure
If the measles vaccine is given within 72 hours of exposure to the virus, it may prevent the illness in some cases. Immune globulin may be given if you can't receive the vaccine or were exposed more than 72 hours ago. The immune globulin acts as an antibody to help your body fight the virus. If it's given within six days of the exposure, it may make the illness milder or prevent it completely. This is especially important for children under age 1, pregnant women and people who have weak immune systems.