[20190603]IN11125_麻疹爆发、疫苗犹豫和联邦政策选择.pdf

Congressional Research Service 1 Measles Outbreaks, Vaccine Hesitancy, and Federal Policy Options Kavya Sekar Analyst in Health Policy Sarah A. Lister Specialist in Public Health and Epidemiology Updated June 3, 2019 As of May 31, 2019, 981 cases of measles across 26 U.S. states have been reported to the Centers for Disease Control and Prevention (CDC)the highest annual number of measles cases since 1992 (with no deaths reported). Figure 1 shows annual measles cases in the past 10 years. Measles is a highly contagious viral illness that can lead to pneumonia, encephalitis (infection of the brain), and, rarely, death. Certain groups are at greater risk for complications (e.g., children under 5 and adults over 20 years of age). No specific treatment exists, but it can be prevented with a vaccine. According to CDC, before a vaccine became available in 1963, there were an estimated 3 million to 4 million annual U.S. measles cases, with an annual average of approximately 48,000 hospitalizations and 400-500 hundred deaths. Widespread vaccination has curtailed ongoing measles transmission. Accordingly, measles was declared eliminated (i.e., no ongoing disease transmission for at least 12