CAUSED BY A PARAMYXOVIRUS, measles (rubeola) is a highly contagious, potentially severe and deadly acute viral disease spread via respiratory droplets that can remain in the air for up to 2 hours after an infectious person leaves the area.1,2 Approximately 9 out of 10 susceptible persons who've been in close contact with a person with measles will develop the disease.3
Measles was once a common childhood illness until the measles vaccine was licensed for use in 1963. In 2000, measles was declared eliminated from the United States; however, the number of cases has been increasing. At the time this issue went to press, the latest 2015 statistics from the CDC were 170 cases in 17 states and Washington, DC.4 Most cases involve people who haven't been vaccinated against measles. Those most at risk include infants and children who are under age 12 months who are too young to be vaccinated; over age 12 months who haven't had at least one measles-mumps-rubella (MMR) vaccine; or over age 4 who haven't had a second MMR vaccination.2
Nurses are often the first clinicians to assess a patient with measles, so they must be able to recognize signs and symptoms of the disease.
Recognizing signs and symptoms
The incubation period begins after measles virus entry via the respiratory mucosa or conjunctivae and lasts for 6 to 19 days, during which most patients are asymptomatic.5 Signs and symptoms of measles typically begin 7 to 14 days after exposure with malaise; anorexia; fever (as high as 105° F [40° C]; pharyngitis; and cough, coryza (rhinitis), and conjunctivitis (known as the “three Cs”).2 About 14 days after a person is exposed, Koplik spots may appear on the buccal mucosa. These 1- to 3-mm whitish, grayish, or bluish elevations with an erythematous base are usually seen opposite the molar teeth, though they can spread to cover the buccal and labial mucosa as well as the hard and soft palate. They have been described as “grains of salt on a red background,” may coalesce, and generally last 12 to 72 hours.5
Three to 5 days after the start of signs and symptoms, an erythematous and maculopapular blanching rash will appear, typically starting on the face and spreading down to the neck, trunk, and extremities (the palms and soles are rarely involved).2,3,5 The lesions may become confluent, especially on the face. The rash may have some petechiae, and in severe cases may appear hemorrhagic. The extent and degree of confluence of the rash correlates with the severity of the illness in children. The rash usually lasts 6 to 7 days, improving within 48 hours after its appearance and darkening to a brownish color and beginning to fade after 3 to 4 days.5
Patients are considered contagious from 4 days before to 4 days after the rash appears. Immunocompromised patients don't always develop a rash.2
Common complications of measles include otitis media, laryngotracheobronchitis, and diarrhea.3 More serious complications include pneumonia and encephalitis.2
Measles is usually diagnosed based on the patient's history and clinical presentation, but immunoglobulin M antibody testing, polymerase chain reaction testing, or viral culture may be needed to confirm the diagnosis.5
Because it's so highly communicable, measles is a CDC Nationally Notifiable Infectious Disease Surveillance System reportable infection.
Prevention of disease spread
Patients suspected of having measles should enter healthcare facilities through a separate entrance (such as a dedicated isolation entrance), if available.
Place the patient immediately in an airborne infection isolation room (AIIR); if an AIIR isn't available, give the patient a facemask and immediately place the patient in an exam room with a closed door. Instruct the patient to keep the facemask on while in the exam room, if possible, and to ask for a new one if it becomes wet. Initiate protocol to transfer the patient to a healthcare facility that has the recommended infection-control capacity to properly manage the patient.6 If a patient's condition doesn't warrant hospitalization, advise the patient to self-quarantine at home under the direction of the local health department. Make sure the patient knows exactly what “self-quarantine” means.
When caring for the patient, wear a fit-tested N95 or higher level disposable respirator; the respirator should be put on before entering the room and removed after exiting the room. Wear gloves and gown and goggles or a face shield. Perform hand hygiene before and after touching the patient and after contact with respiratory secretions and/or body fluids and contaminated objects/materials.6 Instruct the patient to wear a facemask when exiting the exam room, avoid contact with other patients, and practice respiratory hygiene and cough etiquette.6
All healthcare providers should have proof of measles immunity (see CDC guidelines for “proof” criteria, available online at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6204a1.htm) and follow airborne transmission precautions, in addition to standard precautions, as outlined above.
Treatment and prevention
No specific antiviral therapy for measles is available. Treatment is supportive to help relieve symptoms and address complications and includes antipyretics, fluids, and antibiotics to treat bacterial superinfections.5 Severe measles in children is treated with vitamin A, which is administered immediately on diagnosis and repeated the next day.3 The mechanism of action is unknown, but vitamin A given to children with measles in developing countries has been associated with decreased morbidity and mortality. It's thought that vitamin A may correct a viral-induced state of hyporetinemia.5
To prevent measles, the MMR vaccine is given to children in two doses: the first at 12 to 15 months and another prior to school entry at ages 4 to 6. The MMR vaccine can be used in children age 12 months through 12 years. Children between ages 1 and 12 may receive a “combination” vaccine called MMRV, which contains both MMR and varicella vaccines. Adults should get the MMR vaccine if they were born after 1956 unless they have already had measles.7
The MMR vaccine is contraindicated in patients who are pregnant or may become pregnant within 4 weeks, patients with severe immunodeficiency, such as severely symptomatic HIV infection, and those with a history of anaphylaxis triggered by the vaccine or any of its components, including the antibiotic neomycin. Teach patients that risks such as allergic reactions can occur with the MMR vaccine, but getting the vaccine is much safer than getting measles.7