Measles is becoming more prevalent due to voluntary declines in vaccination rates. According to the World Health Organization there have been 41,000 cases of measles in Europe with 40 fatalities thus far in 2018. Measles is less common in the United States, as the Centers for Disease Control and Prevention have reported only 142 cases thus far in 2018. However, there is growing concern for reemergence given the declining number of vaccinations. The 142 cases in 2018 span across 25 different states and account for a total of 11 outbreaks (defined as > 3 linked cases).
Most individuals who contract measles are unvaccinated. In order to prevent outbreaks of measles 95% of the population must be vaccinated. Some areas of Europe have a < 70% vaccination rate at the present time. It is recommended that children receive the measles vaccine at 12-15 months of age and then again at 4-6 years of age. If both doses are given, the vaccine is 97% effective in preventing measles. A single dose is 93% effective in preventing the disease.
Vaccination led to a 99% reduction in measles cases in the United States and a dramatic decrease in other industrialized nations. However, anti-vaccination movements have shown an uptrend in the rates of the disease. Parents may choose not have their children vaccinated, which decreases the overall number of immune individuals and diminishes herd immunity. Some states have robust education programs to teach the public about the importance of vaccinations, but media news outlets reported that Arizona was recently forced to close their education program due to pressure from anti-vaccination programs.
Measles is an RNA virus spread by respiratory droplets or direct contact, though the virus does not live very long on surfaces. The incubation period is ~ 10 days. The symptoms begin with fever and a subsequent rash. Patients may demonstrate Koplik’s spots, which are blue-white dots along the oral mucosa measuring about 1mm. As Koplik’s spots begin to fade, patients develop the characteristic erythematous, confluent rash of measles, which occurs about 2 weeks after initial infection, or about 4 days after the onset of fever. It often begins around the ears and hairline, progressing to the face, trunk, upper extremities, and then lower extremities. The rash begins to fade about 3-4 days after onset. Additional symptoms experienced by patients include cough, conjunctivitis, abdominal pain, nausea, vomiting, diarrhea, and myalgias.
Most complications associated with measles are due to secondary bacterial infections, such as acute laryngotracheobronchitis (croup), otitis media, and bronchopneumonia. Prompt treatment and recognition of these complications are essential to decrease morbidity and mortality. Post-measles encephalomyelitis is a rare complication impacting 1 in 1,000 cases. It is characterized by fever, seizures, and neurologic abnormalities. It is believed to be an autoimmune disorder triggered by the measles virus.
Treatment is largely supportive with use of antipyretics and hydration. No antiviral has been proven effective against measles. Vitamin A therapy has been shown to decrease morbidity and mortality in those that are deficient. Administration recommendations vary based on region and acuity of the patient’s condition. Regional guidelines should be sought prior to making the decision to prescribe vitamin A for treatment of measles.
World Health Organization: Regional Office for Europe: Measles Cases Hit Record High in Europe Region
Centers for Disease Control and Prevention: Measles (Rubeloa)
Harrison's Principles of Internal Medicine, 20e: Chapter 200: Measles (Rubeola)