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A highly communicable disease caused by the rubeola virus and marked by fever, general malaise, sneezing, nasal congestion, brassy cough, conjunctivitis, spots on the buccal mucosa (Koplik spots), and a maculopapular eruption over the entire body. The occurrence of measles before age 6 months is relatively uncommon because of passively acquired maternal antibodies from the immune mother.
SYN: SEE: first disease; SEE: rubeola
An attack of measles almost invariably confers permanent immunity. Active immunization can be produced by administration of measles vaccine, preferably that containing the live attenuated virus although temporary immunity can be attained by administration of measles vaccine containing the inactivated virus for those in whom the live attenuated type is contraindicated. Vaccination has reduced the occurrence of measles during childhood, making it more prevalent during adolescence and adulthood. Measles remains a major cause of death in children in underdeveloped countries, where vaccination is less frequently employed. Passive immunization is afforded by administration of gamma globulin.
Universal vaccination in the U.S. has virtually eliminated the disease domestically. In 2013, more than 160 cases were identified in the U.S., of which approx. 98% were among immigrants. Before vaccination, approx. 450,000 domestic cases were reported in the U.S. annually.
SYMPTOMS AND SIGNS
Measles is spread by inhalation of contaminated air. The incubation period is from 8 to 14 days. Greatest communicability occurs during the prodromal period, which occurs approximately 11 days after exposure to the virus. The onset of symptoms is gradual and includes coryza, rhinitis, drowsiness, loss of appetite, and gradually increasing temperature for the first 2 days up to 101° to 103°F (38.3° to 39.4°C). Koplik spots appear on the buccal mucosa opposite the molars on the second or third day. The fever peaks about the fourth day, at times as high as 104° to 106°F (40° to 41.1°C). Photophobia and cough soon develop; when this happens, the temperature may fall somewhat.
At this time, the rash appears, first on the face as small red maculopapular lesions that grow rapidly and coalesce in places, often causing a swollen, mottled appearance. The somewhat pruritic rash extends outward to the rest of the body and extremities and in some areas may resemble the rash of scarlet fever.
Ordinarily, the rash lasts 4 to 5 days; as it subsides, the temperature declines. Consequently, 5 days after the appearance of the rash, the temperature should be normal or about normal in uncomplicated cases. Early in the disease, leukopenia may be present. More severe symptoms and complications occur in the very young, in adolescents and adults, and in anyone who is immunocompromised or vitamin A deficient.
Encephalitis is a grave complication; among patients who develop this, about one in eight will die, about half will have permanent central nervous system injury, and the remainder will recover completely. Bronchopneumonia is a serious complication. Otitis media, followed by mastoiditis, brain abscess, or even meningitis, is not rare, and unilateral or bilateral nerve deafness may be a permanent consequence. Cervical adenitis, with marked cellulitis, sometimes proves fatal. Tracheitis and laryngeal stenosis, due to edema of the glottis, are sometimes seen in the course of measles. A marked conjunctivitis usually occurs.
Signs and symptoms of scarlet fever and German measles may mimic those of measles. Koplik spots are pathognomonic for measles, however, and if seen, virtually rule out other diagnoses.
All children who have not had measles or who have been vaccinated before age 12 months should be immunized with live attenuated measles vaccine at 12 to 15 months of age. A second dose is recommended at the start of school (5 to 6 yr) or at junior high school age (11 to 12 yr). Measles vaccine is often given in conjunction with mumps and/or rubella virus vaccines. Measles is endemic in many developing countries. In 2000, in nations where measles vaccination was unavailable, more than three quarters of a million children died of the disease. As a result, measles vaccination is now recommended before international travel, including travel to Europe.
Live attenuated vaccine is contraindicated in pregnant women or in those who have leukemia, lymphomas, and other generalized neoplasms; in those taking agents such as steroids and antimetabolites; in persons with active, untreated tuberculosis, HIV, or other severe illness; in those who are sensitive to neomycin or duck or chicken eggs; and after blood transfusion or injection of immune serum globulin. In the latter situation, a 12-week waiting period is necessary before administering the vaccine. Although people with AIDS or HIV infection with signs of serious immunosuppression should not be given MMR, those with HIV infection without symptoms can and should be vaccinated against measles.
Measles is endemic in many developing countries. In 2000, in nations where measles vaccination was unavailable, more than three quarters of a million children died of the disease.
Measles immune serum globulin is used for passive protection in unimmunized, high-risk patients (such as those who have cancer or are taking antimetabolic drugs); if given later than the third day of the incubation period, however, it may only extend the incubation period instead of preventing the disease.
IMPACT ON HEALTH
The prognosis is favorable in the healthy child, but the seriousness of the possible complications of measles should not be minimized. As said above, an attack of measles nearly always confers permanent immunity.
The importance of immunization of children to prevent measles should be emphasized to parents and family caregivers. Patients who contract the disease should remain isolated (droplet isolation) from diagnosis until 4 days after the rash appears. Bedrest and a quiet, calm environment are provided. A dimly lit room can help to counteract the effects of photophobia should it occur. Eye secretions are removed with warm saline or water. The child should avoid rubbing his eyes. Supportive care includes adequate fluid intake, antipyretics as necessary, a cool mist vaporizer to relieve cough and coryza, and antipruritic medication to prevent itching. Parents also should be made aware that cough preparations and antibiotics are usually ineffective. The parents are taught about the importance of hand hygiene and care of contaminated articles. Assessments are made for complications of otitis media, pneumonia, mastoiditis, brochiolitis, laryngotracheitis with obstructive edema, and encephalitis, all of which require early management. The severity of the illness in adults may be reduced by IV ribavirin administration, but this medication is not approved for use by the Food and Drug Administration.