Since 2000, measles cases in the US have been attributed largely to travelers bringing the disease into the country. In recent years, however, measles has become increasingly common, with the number of cases climbing above 150 in 2013, and then jumping to 644 last year – the most cases recorded in a single year since the late 1990s.
2000年以来，美国麻疹病例大部分归因于旅行者携带入境。但是，近几年来，麻疹日益普遍，2013年病例数达到了150以上，去年又增加至644人——这是20世纪90年代以来全年报告人数最多的一年。今年已经有了改写这一纪录的趋势。