乔纳森·波特、菲尔·霍尔姆报道：今年是美国自1991年以来麻疹疫情最严重的一年。自去年年初起，德克萨斯州、犹他州、南卡罗来纳州以及如今的宾夕法尼亚州等地均出现了大规模疫情。
JONATHAN POET, PHIL HOLM The U.S. is enduring its worst year for measles since 1991. Since the beginning of last year, large outbreaks have been reported in several states, including Texas, Utah, South Carolina and, now, Pennsylvania.
今年的病例呈现波浪式增长趋势：年初出现一波高峰，入秋后又迎来新一轮爆发。目前全美各地均有麻疹病例报告，其中宾夕法尼亚州、南卡罗来纳州和犹他州疫情最为严重，仅有五个州尚未出现任何病例。
The year’s cases have come in waves, with one earlier this year and another as summer turned to fall. Measles cases have been reported across the country. Pennsylvania, South Carolina and Utah have seen the most. Only five states haven’t reported any cases.
2000年美国曾宣布成功消除麻疹，即该疾病不再在国内持续传播。多年来美国报告的病例数量一直较少。然而如今，由于部分人群未接种疫苗，导致出现了多起聚集性疫情——医学上将三例及以上相互关联的病例定义为聚集性疫情。
Measles was declared eliminated in the United States in 2000, meaning the disease was no longer continuously spreading in the country. For years, the U.S. saw relatively few cases. Now, pockets of unvaccinated residents are allowing outbreaks – defined as three or more related cases – to spring up. Children and teenagers account for most confirmed cases.
在已确诊的病例中，儿童和青少年占绝大多数。绝大多数患者要么未接种过疫苗，要么接种情况不明。公共卫生专家一致认为，接种麻疹疫苗是预防该疾病的最有效手段。
The overwhelming majority of people who have contracted measles were either unvaccinated or had an unknown vaccination status. Public health officials agree that the best way to protect yourself from measles is getting a vaccine.